To see the other types of publications on this topic, follow the link: Singly Reinforced Concrete Walls.
Journal articles on the topic 'Singly Reinforced Concrete Walls'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Singly Reinforced Concrete Walls.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Kang, Yan Bo, Shi Min Huang, and Qiu Lai Yao. "Comparative Study on Shear Wall and Brick Wall Strengthened with Reinforced Concrete Splint." Advanced Materials Research 639-640 (January 2013): 1108–13. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.1108.
Full textAbstract:
The test process and analysis of 3 walls and the expand calculation about walls are introduced in this paper. Through a series of low-cycle repeated load experiments, the paper do comparative studies on the seismic behavior of concrete shear wall and brick wall strengthened with reinforced concrete splint firstly. Because of the limitations of experiment, the study focuses on the unreinforced brick wall, the 120mm shear wall, the brick wall strengthened with double 60mm reinforced concrete splint and the brick wall strengthened with single 60mm reinforced concrete splint. On the basis of the experiment, we use the finite element software to establish a rational numerical model. Through the finite element analysis, the paper expands the calculation about walls and makes up for the lack of experimental research. Based on the analysis results, we get the conclusion that the reinforced concrete splint can enhance the seismic behavior of the unreinforced brick wall. Taking no consideration of structures’ integral stability, the seismic behavior of brick wall strengthened with double 60mm reinforced concrete splint is equivalent to the 120mm shear wall.
2
Zhang, Jianwei, Wenbin Zheng, Cheng Yu, and Wanlin Cao. "Shaking table test of reinforced concrete coupled shear walls with single layer of web reinforcement and inclined steel bars." Advances in Structural Engineering 21, no. 15 (May 19, 2018): 2282–98. http://dx.doi.org/10.1177/1369433218772350.
Full textAbstract:
In this study, five 1/4 scaled shaking table tests were conducted to investigate the seismic performance of reinforced concrete coupled shear walls with single layer of web reinforcement and inclined steel bars. The five tested coupled shear walls included three models with normal opening ratio (19%) and two models with large hole ratio (27%). The three models with normal opening included one model with single layer of web reinforcement, two models with single layer of web reinforcement and 75° inclined steel bars in the limbs’ web or at the bottom. Two reinforced concrete coupled shear walls with large hole and single row of reinforcements also were tested with inclined reinforcements or without them. The dynamic characteristics, dynamic response, and failure mode of each model were compared and analyzed. The test and analysis results demonstrate that the inclined steel bars are identified as an efficient means of limiting overall deformation, increasing energy dissipation, and reducing the possible damage by earthquake for reinforced concrete coupled shear walls with single layer of web reinforcement. Thus, reinforced concrete coupled shear walls with inclined steel bars have better seismic performance than reinforced concrete coupled shear walls without inclined steel bars. With appropriate design, reinforced concrete coupled shear walls with single layer of web reinforcement and inclined steel bars can be applied in multi-story buildings.
3
Hube, Matías A., Hernán Santa María, Orlando Arroyo, Alvaro Vargas, Javier Almeida, and Mauricio López. "Seismic performance of squat thin reinforced concrete walls for low-rise constructions." Earthquake Spectra 36, no. 3 (March 11, 2020): 1074–95. http://dx.doi.org/10.1177/8755293020906841.
Full textAbstract:
Thin reinforced concrete (RC) walls with single layer reinforcement have been used for houses and buildings in several Latin American countries. Although some design codes include recommendations for squat thin walls in low-rise constructions, its seismic performance has not been validated adequately in past earthquakes. This article presents the results of an experimental campaign of nine full-scale specimens conducted to characterize the influence of the steel type, the reinforcement ratio, and the wall thickness on the seismic behavior of squat thin RC walls with single layer reinforcement. Both welded wire and deformed bars were used as web reinforcement. Experimental results are used to develop nonlinear models to assess the seismic behavior of a prototype two-story house with welded wire reinforcement and deformed bars by means of incremental dynamic analyses. The experimental results show that the type of steel has the largest influence on wall seismic performance. The numerical results suggest that RC walls with single layer reinforcement are suitable for housing applications up to two stories in high seismicity regions, particularly walls detailed with deformed bars.
4
Chen, Wei, Fang Bo Wu, Xu Hong Zhou, and Hai Lin Huang. "Experimental Investigation of Seismic Behavior of a New Type Masonry Walls." Advanced Materials Research 639-640 (January 2013): 732–39. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.732.
Full textAbstract:
Conventional concrete hollow blocks have vertical single or multiple holes and they have been extensively used in masonry structures and as infill walls in reinforced concrete frame structures. However, most masonry walls using conventional concrete hollow blocks have the shortcoming of poor seismic resistance. A new type concrete hollow block with horizontal-holes has been developed and it could significantly improve the seismic resistance of a masonry wall as well as simplify the construction processes. The new hollow blocks are very easy to build a wall in a construction site and, in particular, they enable a convenient construction of reinforced concrete (RC) horizontal strips in their horizontal cavities and such RC strips can be readily connected to the adjacent RC columns. This provides an innovative seismic resistant measure to enhance the seismic resistance of masonry walls. In order to evaluate the seismic behavior of the new type masonry walls, an experimental investigation was carried out and seven full scale wall specimens were tested under in-plane cyclic loading. The experimental parameters include the number of horizontal RC strips, strength of the hollow blocks, height/width ratio of a wall and, with or without a window opening in the wall. In this paper, the details of the experimental investigation and the main test results are presented and, the characteristics of the seismic behavior of these wall specimens are discussed in relation to the influence of the experimental parameters.
5
Aksenov, V. N., Vu Le Quyen, and E. V. Trufanova. "Evaluation of Reinforced Concrete Cylindrical Reservoirs with Single-layered Walls." Procedia Engineering 150 (2016): 1919–25. http://dx.doi.org/10.1016/j.proeng.2016.07.192.
Full text
6
Saarenheimo, Arja, Kim Calonius, Markku Tuomala, and Ilkka Hakola. "Soft Missile Impact on Shear Reinforced Concrete Wall." Journal of Disaster Research 5, no. 4 (August 1, 2010): 426–36. http://dx.doi.org/10.20965/jdr.2010.p0426.
Full textAbstract:
In developing numerical approaches for predicting the response of reinforced concrete structures impacted on by deformable projectiles, we predict structural behavior collapse and damage using simple analysis and extensive nonlinear finite element (FE)models. To verify their accuracy, we compared numerical results to experimental data and observations on impact-loaded concrete walls with bending and transverse shear reinforcement. Different models prove adequate for different cases and are sensitive to different variables, making it important to rely on more than a single model alone. For wall deformation in bending mode, deflection is predicted reasonably well by simple four-node shell elements. Where punching dominates, transverse shear behavior must be considered. Formation of a shear failure cone is modeled using three-dimensional solid elements.
7
Ismail, Najif, Tamer El-Maaddawy, Amanullah Najmal, and Nouman Khattak. "Experimental in-plane performance of insulated concrete and brick masonry wall panels retrofitted using polymer composites." Bulletin of the New Zealand Society for Earthquake Engineering 51, no. 2 (June 30, 2018): 85–91. http://dx.doi.org/10.5459/bnzsee.51.2.85-91.
Full textAbstract:
Masonry infilled reinforced concrete frame buildings built prior to the introduction of modern seismic provisions have been observed to undergo damage in and around the masonry infill walls during most recent moderate to severe earthquakes. Fibre reinforced cementitious matrix (FRCM) is one of several retrofitting options available to limit such earthquake induced damage to infill walls. An experimental program was undertaken herein to experimentally investigate the effectiveness of FRCM as a strengthening solution for vintage (i.e. built between 1880 and 1930) un-reinforced brick masonry (URM) and insulated concrete masonry (IMU) infill walls. A total of 16 masonry assemblages were tested under in-plane diagonal load, of these 8 were constructed replicating vintage URM whereas the remainder were constructed using modern IMU. IMU is a preferred masonry type in hot and humid regions owing to its superior insulting capability. Different polymer fabrics (i.e., carbon, glass and basalt) were applied over both faces of test walls, with two replicate test walls receiving the same FRCM strengthening details. One test wall of each masonry type was tested as-built to serve as a control specimen for comparison. One wall of each masonry type received two layers of basalt FRCM. The investigated aspects included stress-strain behaviour, stiffness, and ductility. Shear strength increment observed due to single layer of FRCM application was 422-778% for vintage URM and 307-415% for modern IMU. FRCM also substantially increased the ductility capacity of the masonry assemblages.
8
Marsono, Abdul Kadir, and Somaieh Hatami. "Evaluation of Coupling Beams Behavior Concrete Shear Wall with Rectangular and Octagonal Openings." Applied Mechanics and Materials 735 (February 2015): 104–8. http://dx.doi.org/10.4028/www.scientific.net/amm.735.104.
Full textAbstract:
Reinforced concrete coupled walls are cantilevered shear walls joined by coupling beams and are used in high-rise apartment for many years. Rectangular openings are the most common shape of openings used in shear wall in order to provide doors, windows, entrance to car park areas and elevators or staircases. Behavior of coupling beams affect the strength of coupled walls. This research suggests adding haunches to the corners of rectangular openings and form octagonal openings as a method to increase the strength of coupling beams. The experimental results of shear wall with single band of rectangular and octagonal openings are compared in terms of behavior of coupling beams under cyclic load. The results demonstrate that the coupling beams in shear wall with octagonal openings are stronger than coupling beams in shear wall with rectangular openings.
9
Mander, Thomas J., and Zachery I. Smith. "Composite Steel Stud Blast Panel Design and Experimental Testing." Applied Mechanics and Materials 82 (July 2011): 479–84. http://dx.doi.org/10.4028/www.scientific.net/amm.82.479.
Full textAbstract:
Based on Federal Aviation Authority (FAA) requirements, project specific blast loads are determined for the design of a new airport traffic control tower. These blast loads must be resisted by exterior wall panels on the control tower, protecting building occupants from intentional explosives attack scenarios. Such blast resistant walls are typically constructed of thick reinforced concrete panels or composite steel plate and rolled sections, as conventional building cladding systems have relatively low blast resistance. While these more robust design approaches are valid, the additional cladding mass they represent will significantly increase the base shear and overturning demand in seismic zones. This paper investigates the use of a light structural system comprised of a steel stud wall assembly partially embedded in a thin layer of concrete to obtain composite action. Fiber reinforced polymer (FRP) composites are also included to increase the blast resistance and aid in keeping the panel weight to a minimum. Two full-scale composite steel stud walls are designed, constructed, and tested dynamically in the BakerRisk shock tube. The stud walls consist of back-to-back 150 mm deep, 14 gauge (1.8 mm thick), cold-formed steel studs spaced at 610 mm on center. Both specimens have a 50 mm thick normal weight concrete layer, reinforced with welded wire mesh that is welded to the stud compression flanges to achieve composite action. Two layers of Tyfo® SEH-51A fiber reinforced composites are used on the tension flange of the steel studs. A single layer of Tyfo® SEH-51A composites is used on the tension face of the concrete layer between the studs for one of the specimens. Web stiffeners are used at the bearing support to prevent premature web crippling shear failure of the specimens. The stud walls are analyzed using single-degree-of-freedom (SDOF) models. A non-linear moment-curvature relationship, accounting for actual material constitutive properties, is used for determining the resistance function of the walls. Blast pressure and impulse data from the shock tube tests is used to compare analytical predictions to the measured displacement-time response. Analytical predictions of panel response for both tests are within ten percent of the observed response based on displacement.
10
Gur, Turel, AliCihan Pay, Julio A. Ramirez, Mete A. Sozen, Arvid M. Johnson, Ayhan Irfanoglu, and Antonio Bobet. "Performance of School Buildings in Turkey During the 1999 Düzce and the 2003 Bingöl Earthquakes." Earthquake Spectra 25, no. 2 (May 2009): 239–56. http://dx.doi.org/10.1193/1.3089367.
Full textAbstract:
Several school buildings were surveyed in the disaster areas of the Marmara (17 August 1999, [Formula: see text]), Düzce (12 November 1999, [Formula: see text]), and Bingöl (1 May 2003, [Formula: see text]) earthquakes in Turkey. Among them, 21 reinforced concrete buildings were found to have an identical floor plan. Lateral load resisting structural system consisted of reinforced concrete frames (moment-resisting frame) in 16 of the buildings and structural concrete walls integrated with the moment-resisting frame (dual system) in the remaining five buildings. The number of stories above ground in these buildings ranged from two to four. These school buildings provide a nearly ideal test of the effect of a single important structural characteristic on the performance of buildings with structural designs that are uniform in all other respects. Our observation is that the presence of structural walls improves the behavior of reinforced concrete systems drastically.
11
Chen, Zhihua, Jingshu Wu, Jiadi Liu, and Chenghe Hu. "Out-of-Plane Bending and Shear Behaviors of Steel Plate-Concrete Walls for Nuclear Power Plants." Advances in Civil Engineering 2020 (May 11, 2020): 1–16. http://dx.doi.org/10.1155/2020/2765193.
Full textAbstract:
The steel plate-concrete structure, with its advantages of modular construction, good seismic capacity, and strong impact resistance, has been gradually replacing the reinforced concrete structure in the containment vessel and internal workshop structure of nuclear power plants in recent years. In this study, the out-of-plane single-point loading test and parametric finite element simulation analysis were conducted on five steel plate-concrete wall slab specimens with different stud spacings, shear span ratios, and steel contents. Results showed that the steel plate-concrete wall slab under the out-of-plane load had the same failure mode as that of an ordinary reinforced concrete wall. The out-of-plane shear capacity of the steel plate-concrete wall slab increased significantly in the case of numerous studs. With the increase in shear span ratio, steel plate-concrete members suffered a bending failure. When the steel content was low, they had diagonal tension failure, such as a rare-reinforced concrete wall. The out-of-plane bending and shear mechanism of the steel plate-concrete shear wall was studied theoretically, and the calculation formulas of the bending and shearing capacities were derived.
12
Marsono, Abdul Kadir, and Somaieh Hatami. "Analysis of reinforced concrete shear walls with single band of octagonal openings." KSCE Journal of Civil Engineering 20, no. 5 (November 23, 2015): 1887–94. http://dx.doi.org/10.1007/s12205-015-0512-z.
Full text
13
Jacques, Eric, Alan Lloyd, and Murat Saatcioglu. "Predicting reinforced concrete response to blast loads." Canadian Journal of Civil Engineering 40, no. 5 (May 2013): 427–44. http://dx.doi.org/10.1139/l2012-014.
Full textAbstract:
Computer software was developed for inelastic analysis of structural members subjected to blast-induced shock waves. The software can predict the dynamic response of structural elements, provided the load–deformation characteristics are defined. The software has built-in capabilities to generate the load–deformation characteristics of common structural and non-structural members. Currently this capability includes reinforced concrete columns, one-way walls, beams, and one-way slabs. The input consists of member geometry, boundary conditions, dynamic material properties, explosive threat parameters, and desired performance levels. The results are presented in graphical format in terms of structural load–deformation characteristics, single degree of freedom displacement – time histories and iso-displacement pressure–impulse diagrams. The program was verified extensively using experimental data generated from simulated explosive loading of reinforced concrete members at the University of Ottawa shock tube testing facility. The shock tube has been shown to generate a wide range of pressure–impulse combinations, accurately simulating free-field detonation of high explosives of various mass and standoff distances.
14
Henry, R. S. "Assessment of minimum vertical reinforcement limits for RC walls." Bulletin of the New Zealand Society for Earthquake Engineering 46, no. 2 (June 30, 2013): 88–96. http://dx.doi.org/10.5459/bnzsee.46.2.88-96.
Full textAbstract:
During the 2010/2011 Canterbury earthquakes, several reinforced concrete (RC) walls in multi-storey buildings formed a single crack in the plastic hinge region as opposed to distributed cracking. In several cases the crack width that was required to accommodate the inelastic displacement of the building resulted in fracture of the vertical reinforcing steel. This type of failure is characteristic of RC members with low reinforcement contents, where the area of reinforcing steel is insufficient to develop the tension force required to form secondary cracks in the surrounding concrete. The minimum vertical reinforcement in RC walls was increased in NZS 3101:2006 with the equation for the minimum vertical reinforcement in beams also adopted for walls, despite differences in reinforcement arrangement and loading. A series of moment-curvature analyses were conducted for an example RC wall based on the Gallery Apartments building in Christchurch. The analysis results indicated that even when the NZS 3101:2006 minimum vertical reinforcement limit was satisfied for a known concrete strength, the wall was still susceptible to sudden failure unless a significant axial load was applied. Additionally, current equations for minimum reinforcement based on a sectional analysis approach do not adequately address the issues related to crack control and distribution of inelastic deformations in ductile walls.
15
Gorantla, Kiran Kumar, Saboor Shaik, and Ashok Babu Talanki Puttaranga Settee. "Simulation of Various Wall and Window Glass Material for Energy Efficient Building Design." Key Engineering Materials 692 (May 2016): 9–16. http://dx.doi.org/10.4028/www.scientific.net/kem.692.9.
Full textAbstract:
Buildings consume huge amount of energy for forced ventilation and artificial day lighting. Use of appropriate material combinations for walls and window glass can help in reducing energy consumption for cooling and lighting. This paper presents the thermal properties of four building materials such as, laterite stone, dense concrete, burnt brick and mud brick. It also presents the experimentally measured optical properties of glass materials such as, clear glass, bronze glass, green glass and reflective. In this study building of size 5m X 5m X 3.2m with four wall materials and four glass materials were designed using design builder software. The thickness of the wall was considered as external wall with thickness 0.22m. All the walls covered with cement plaster on either side. Roof of the building is made of reinforced cement concrete and floor is dense concrete. Thermal analysis was carried out using by Energy plus software. Single sized glass windows were placed in south direction (Due to less heat gain in south direction) for Mangalore city (12.870N, 74.880E), Karnataka, India. Different window to wall ratios (20%, 40%, 60%, 80% and 100%) were maintained for buildings. Total eighty building models were investigated for heat gain into buildings. From the results, it is observed that irrespective of the window to wall ratio, mud brick walls with reflective window glass were observed to be energy efficient from the lower heat gain point of view, and laterite stone wall building with clear glass windows were observed to be the worst due to their higher heat gain values. At 60% window to wall ratio mud brick walls with reflective window glass have 24.93kWh heat gain and dense concrete walls with clear glass have 32.9 kWh heat gain. The results of the study help in establishing the best combination of wall and glass materials for minimum heat gain into buildings.
16
Shah, Syed Azmat Ali, Khan Shahzada, and Qazi Samiullah. "INFLUENCE OF BRICK MASONRY INFILLED WALL ON SEISMIC PERFORMANCE OF REINFORCED CONCRETE FRAME." NED University Journal of Research XVII, no. 3 (June 30, 2020): 15–29. http://dx.doi.org/10.35453/nedjr-stmech-2018-0013.
Full textAbstract:
Infilled walls are considered as nonstructural elements in reinforced concrete (RC) frame buildings. However, they can interact with the bounding frame when subjected to lateral load and can change the load resisting mechanism and failure pattern. This paper presents the results of two full scale (single storey and single bay) RC frames which were tested using quasi-static loading. Of these, one was a bare frame whereas the second frame was constructed with infilled brick masonry wall. The data of hysteresis curves, strength, capacity curve, stiffness, energy dissipation, displacement ductility, overstrength factor, response modification factor and performance levels have been presented and discussed. The test results highlighted the positive influence of infilled wall on stiffness, strength, energy dissipation and ductility of RC frame. It was also observed that response modification factor is sensitive to the frame geometric configuration.
17
Eroğlu, Nur, Sena Aral, Sinan Melih Nigdeli, and Gebrail Bekdaş. "Jaya algorithm based optimum design of reinforced concrete retaining walls under dynamic loads." Challenge Journal of Structural Mechanics 7, no. 2 (June 23, 2021): 64. http://dx.doi.org/10.20528/cjsmec.2021.02.002.
Full textAbstract:
In this study, the optimum dimensioning of a reinforced concrete retaining wall that meets the safety conditions under static and dynamic loads in terms of cost has been performed using Jaya algorithm, which is one of the metaheuristic algorithms. In the optimization process, reinforced concrete design rules and ground stress, sliding and overturn tests have been determined as design constraints for the safe design of the retaining wall. While 5 cross-section dimensions of the retaining wall are defined as the design variable, the objective function is targeted as the total cost per unit length of the retaining wall. In the study, optimum results are also presented by examining the changes of the toe projection length of the retaining wall, which is one of the design variables, narrowing between 0.2-10 m. The design variables minimizing the objective function were found via Jaya algorithm that have single-phase. In addition to achieving optimum dimensioning results in terms of safety and cost with the optimization method used as a result of the reinforced concrete design made by applying the rules of the regulation on buildings to be constructed in earthquake zones, the change in cost in seismic and static conditions was examined.
18
Jin, Huan. "Comparative Study on the Effects of Infill Walls on Reinforced Concrete Frame Structures." Applied Mechanics and Materials 730 (January 2015): 81–84. http://dx.doi.org/10.4028/www.scientific.net/amm.730.81.
Full textAbstract:
Based on the quasi-static test of single-layer, two-bay RC frame model, using DIANA finite element program, a finite element Macro-model of masonry-infilled frame structure was established, and nonlinear finite element analysis of frame structures filled with different masonry materials was conducted. As a result of the existence of infill walls, the failure modes of frame structure have been changed, and which is easy to cause shear failure at the top of frame columns. If masonry materials of infill walls are different, the effects of infill panels on frame structures will be different. Comparative analysis shows that the influence of clay bricks is the largest, followed by autoclaved bricks’ influence, while aerated concrete blocks’ influence is the smallest. Therefore, to avoid the associated failure mechanism caused by infill walls, lightweight masonry materials are suggested to be used in actual engineering.
19
Massone, Leonardo M., and Marco A. Ulloa. "Shear response estimate for squat reinforced concrete walls via a single panel model." Earthquakes and Structures 7, no. 5 (November 25, 2014): 647–65. http://dx.doi.org/10.12989/eas.2014.7.5.647.
Full text
20
Kawan, Chandra Kiran. "Effect of stiffeners in lateral stiffness of masonry infill reinforced concrete (RC) frames." Journal of Science and Engineering 3 (December 1, 2015): 7–20. http://dx.doi.org/10.3126/jsce.v3i0.22383.
Full textAbstract:
Infilled frames are reinforced concrete frames with masonry infill. The provision of masonry walls as infill increases the lateral stiffness of frame. Unreinforced masonry infill effects the strength and stiffness of frame but being ignored for a long time. The main objective of this paper is to study the individual and combined effect of infill masonry wall, stiffeners and wooden frame in the lateral stiffness of infill reinforced concrete frame with central opening, with and without gap element consideration. From the analysis using SAP software, it is observed that with increase in openings, stiffness decreases but introducing stiffeners and wooden frame increases the lateral stiffness. Embedding the gap element as the boundary condition reduces the stiffness of the infilled frame. Numerical investigations are carried out by finite element modeling for analyzing the behavior of infilled frame. The single equivalent diagonal strut width was determined by obtaining the same lateral stiffness from finite element model, and also strut reduction factor for different conditions with central openings are proposed.
21
Calabrese, Angelo Savio, Pierluigi Colombi, and Tommaso D'Antino. "A Bending Test Set-Up for the Investigation of the Bond Properties of FRCM Strengthenings Applied to Masonry Substrates." Key Engineering Materials 817 (August 2019): 149–57. http://dx.doi.org/10.4028/www.scientific.net/kem.817.149.
Full textAbstract:
Existing masonry and reinforced concrete structures are characterized by a wide use of structural and non-structural masonry members such as structural walls, infill walls, arches, vaults etc. All these members are characterized by high vulnerability when subjected to seismic events, since unreinforced masonry has a negligible tensile strength. The use of fiber reinforced polymers (FRP) composites has become a common practice and it represents a light-weight, easy, fast, and non-invasive solution for rehabilitation of existing masonry structures. Fabric reinforced cementitious matrix (FRCM) are relatively newly developed composite materials, representing a valid alternative to FRP in strengthening and retrofitting of existing reinforced concrete and masonry structures. Despite of the numerous advantages guaranteed by the inorganic matrix, the bond-behavior between the fibers and the embedding matrix is still under investigation. Different set-ups have been proposed in the literature to study the bond behavior of FRCM composites. Among them, single-and double-lap shear tests are the most commonly used. In this paper, the bond behavior of a polyparaphenylene benzobisoxazole (PBO) FRCM composite applied to masonry elements is studied using a bending and a single-lap shear test set-up. The bond capacities obtained by the two set-ups are analyzed and discussed.
22
Yee, Hooi Min, Rohamezan Rohim, and Ong Chong Yong. "Experimental Study on Bending Capacity of Plain Wall System." Applied Mechanics and Materials 187 (June 2012): 157–60. http://dx.doi.org/10.4028/www.scientific.net/amm.187.157.
Full textAbstract:
Plain wall system is highly suitable to be used with reinforced concrete as its building material. Concrete vertical walls may serve both architecturally partitions and structurally to carry gravity and lateral loading. Moment transfer of joint is an important aspect for proper structurally functioning of plain wall system. Hence, the aim of this study is to investigate experimentally the effect of reinforcement details in the wall on bending capacity for support stiffness in plain wall system in Malaysia. A total of six wall specimens were tested. Three of this specimens consisted single layer of rebar while another three specimen consisted of double layer of rebar. The size of the plain wall’s specimens is 1000mm in length, 1080mm in width, 1000mm in height and 80mm in thickness. The average concrete strength was 23.49MPa with Grade 30N/mm2 and the average yield strength of R5 bar was 817MPa. The bending capacity at failure for single layered of rebar in wall for specimen 1, 2 and 3 were found to be 3.59kNm, 3.81kNm and 3.15kNm, respectively. The bending capacity at failure for double layered of rebar in wall for specimen 1, 2 and 3 were 5.50kNm, 6.31kNm and 7.00kNm, respectively. Based on the results, specimens consisted of double layered of rebar in wall is found to provide higher bending capacity to the joint of plain wall system in the range from 56.25% to 98.86% compared with single layered of rebar in wall.
23
Allouzi, Rabab, and Ayhan Irfanoglu. "Development of new nonlinear dynamic response model of reinforced concrete frames with infill walls." Advances in Structural Engineering 21, no. 14 (April 10, 2018): 2154–68. http://dx.doi.org/10.1177/1369433218768915.
Full textAbstract:
The complex behavior of reinforced concrete frames with infill walls under earthquake loads requires a realistic conceptual model that recognizes changes in strength and stiffness occurring during loading. Accordingly, a new hysteresis model is developed in this article for such reinforced concrete frames to investigate the ultimate damage state given a ground motion. Using this model, the infilled frame can be represented as a single-degree-of-freedom system for computationally efficient dynamic in-plane response analysis. A backbone curve is developed first to provide an envelope within which load–displacement paths occur. Then, the load reversal effects are described and integrated into the backbone curve to obtain the hysteresis model. The hysteresis model developed in this article is checked using data from 11 laboratory experiments carried out by other researchers. The applicability of the hysteresis model is also illustrated on a laboratory specimen that was tested by other researchers under base excitation.
24
Boivin, Yannick, and Patrick Paultre. "Seismic force demand on ductile reinforced concrete shear walls subjected to western North American ground motions: Part 1 — parametric study." Canadian Journal of Civil Engineering 39, no. 7 (July 2012): 723–37. http://dx.doi.org/10.1139/l2012-043.
Full textAbstract:
A parametric study of regular ductile reinforced concrete (RC) cantilever walls designed with the 2010 National building code of Canada and the 2004 Canadian Standards Association (CSA) standard A23.3 for Vancouver is performed to investigate the influence of the following parameters on the higher mode amplification effects, and hence on the seismic force demand: number of storeys, fundamental lateral period (T), site class, wall aspect ratio, wall cross-section, and wall base flexural overstrength (γw). The study is based on inelastic time-history analyses performed with a multilayer beam model and a smeared membrane model accounting for inelastic shear–flexure–axial interaction. The main conclusions are that (i) T and γware the studied parameters affecting the most dynamic shear amplification and seismic force demand, (ii) the 2004 CSA standard A23.3 capacity design methods are inadequate, and (iii) a single plastic hinge design may be inadequate and unsafe for regular ductile RC walls with γw < 2.0.
25
Eusuf, Muhammad Abu, Khairuddin Abdur Rashid, Wira Mohd Noor, and Abdullah Al Hasan. "Shear Wall Construction in Buildings: A Conceptual Framework on the Aspect of Analysis and Design." Applied Mechanics and Materials 268-270 (December 2012): 706–11. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.706.
Full textAbstract:
This study describes the analysis and design process of shear wall construction, which is applied in various types of building construction. Shear walls resist lateral forces viz. earthquake force and wind force for high-rise structure and gravity load for all type of structure. Besides, Buildings with cast-in-situ reinforced concrete shear walls are widely used in earthquake-prone area and regions in the world. Research methods were confined to library research and employed software for analysis. The analytical accuracy of complex shear wall system have always been of concern to the civil and structural Engineering system. The software of this system is performed on the platform of modelling and then, the system models are usually idealized as line elements instead of continuum elements. Single walls are modelled as cantilevers and walls with openings are modelled as pier/ spandrel systems. In order to find the stiffness, the simple systems models can provide reasonable results. It has always been accepted that a scale based model in the FEM is exact and justifiable.
26
ALVA, G. M. S., and G. A. MONTANDON. "Structural models for analysis of reinforced concrete frame buildings with masonry infills." Revista IBRACON de Estruturas e Materiais 12, no. 5 (October 2019): 1058–85. http://dx.doi.org/10.1590/s1983-41952019000500006.
Full textAbstract:
Abstract The behavior of single-storey, single-bay reinforced concrete infilled frame with masonry panel subjected to static horizontal load was studied using two structural models: i) equivalent strut model (ESM) and ii) model with two-dimensional finite elements for state stress plane (MEF). In the first model, an equivalent diagonal strut replaces masonry. The axial stiffness of this element is defined by evaluation of the equivalent diagonal width. In the second model, the infilled frame is modeling by two-dimensional finite elements, requiring the simulation of the sliding and separation between the wall surfaces and the reinforced concrete frame. Although equivalent strut models are more attractive for design, the formulas found in the literature to determine equivalent strut width provide very different values. In addition, most of these formulas ignore some parameters that may be important, such as beam flexural stiffness. For this reason, several numerical analysis were be carried out. The models simulated usual geometric and mechanical characteristics observed in reinforced concrete buildings. The results of the two-dimensional finite element modeling (by software ANSYS) were used as reference for the evaluation of the results provided by the equivalent strut model. The comparison of results allowed the assessment of the analytical expressions for evaluation of the equivalent diagonal width. Based on this assessment, a new expression is proposed for buildings with similar characteristics as analyzed in this paper. The results of numerical simulations with MEF models also allowed for an evaluation of stresses and the probable cracking pattern in infill walls.
27
Liu, Yi, and J. L. Dawe. "Experimental determination of masonry beam-column behaviour." Canadian Journal of Civil Engineering 28, no. 5 (October 1, 2001): 794–803. http://dx.doi.org/10.1139/l01-047.
Full textAbstract:
An experimental program consisting of 36 reinforced concrete masonry wall specimens comprised of 400 × 200 × 150 mm standard units in two series of tests was carried out to investigate the behaviour of masonry walls under combined axial and lateral loading. W2R series specimens had a single layer of vertical steel, and W4R series specimens had a double layer of vertical steel. Test results show that the effective wall stiffness, (EI)eff, differs from currently specified code values in regions where compression failure tends to predominate. Overall test results presented graphically in the form of lateral load versus deflection, axial load versus moment, and (EI)eff versus eccentricity ratio, e/t, indicate that the current Canadian masonry design code underestimates the effective stiffness of walls with eccentricity ratios e/t < 0.4.Key words: beamcolumn, masonry, reinforcement, experimental, rigidity, moment magnifier.
28
Lai, M. C., and Y. C. Sung. "A Study on Pushover Analysis of Frame Structure Infilled with Low-Rise Reinforced Concrete Wall." Journal of Mechanics 24, no. 4 (December 2008): 437–49. http://dx.doi.org/10.1017/s1727719100002550.
Full textAbstract:
AbstractThis paper focused on the pushover analysis of a frame structure infilled with low-rise reinforced concrete (RC) wall. The softening model of concrete as well as the elastoplastic model of reinforcement was considered in the analysis associated with the equilibrium and compatibility conditions. Accordingly, the shear load-deformation relationship of the wall subjected to monotonic lateral load can be analyzed through the proposed analysis procedure. Based on the relationship obtained, we employed a single equivalent structural strut represented by a nonlinear axial member, acting in the diagonal direction of the frame, in simulating the infilled RC wall to simplify the framed wall model. As a result, the sequential pushover analysis of the whole structure could be performed easily and efficiently based on the realistic procedure proposed.To validate the proposed approach, reported results from the cyclic loading tests of fifteen specimens were adopted for the correlation. Based on the correlation, it is found that this study can provide an acceptable result of the pushover analysis and give an insight into progressive failure consequence of the framed wall structure. The proposed procedure simplifying the structural model helps the practical engineers get a higher efficiency while performing seismic evaluation and retrofit design of the high-redundancy frame structure with numerous infilled low-rise RC walls.
29
Deng, Hongyu, and Baitao Sun. "Finite Element Modeling and Mechanical Behavior of Masonry-Infilled RC Frame." Open Civil Engineering Journal 10, no. 1 (March 10, 2016): 76–92. http://dx.doi.org/10.2174/1874149501610010076.
Full textAbstract:
During the analysis of reinforced concrete structures, the infill wall is usually simplified as a diagonal inclined strut to facilitate finite element modeling calculations. However, the actual seismic damage and single frame-filled wall pushover experimental results show that when the earthquake shear force is huge, the top of the infill wall and the beam–column connections are usually, thus the path of the force transfer will be changed. Based on this actual failure phenomenon, a new calculation model which has different contact position between the equivalent bracing walls and the frame columns is generated. Thus, the force analysis is given based on this model, the formulae for calculating the equivalent width of bracing walls, the shear bearing capacity of the wall-filled frame, and the infill wall’s actual participation in the stiffness. A finite element simulation method by ABAQUS is used to determine an empirical formula for calculating the reasonable contact position between the equivalent bracing walls and the frame columns. The verification results show that the finite element model presented in this paper is more reasonable, and the stiffness and shear resistance of infill wall should not be neglected. The calculation formula of stiffness of infill wall presented in this paper is coincided with seismic code. But the calculation formula of shear resistance of infill wall presented in seismic code is higher than the actual value, so it is suggested that calculation formula presented in this paper should be accepted.
30
Arama, Zülal Akbay, Aylin Ece Kayabekir, Gebrail Bekdaş, Sanghun Kim, and Zong Woo Geem. "The Usage of the Harmony Search Algorithm for the Optimal Design Problem of Reinforced Concrete Retaining Walls." Applied Sciences 11, no. 3 (February 2, 2021): 1343. http://dx.doi.org/10.3390/app11031343.
Full textAbstract:
In this paper, the Harmony Search (HS) algorithm is utilized to perform single and multivariate parametric studies to acquire the optimization of both size and cost of reinforced concrete (RC) retaining walls embedded in pure frictional soils. The geotechnical properties of the backfill and foundation soil such as shear strength angle, unit weight, and the ultimate bearing pressure of the soil have been used to create different cases for evaluating the effects of site properties on the size and cost of the wall. The change of depth of excavation and surcharge loading condition is fictionalized for generating different environmental conditions for all envisaged soil profiles to predict possible rates of influences. The unit cost of the concrete has also been evaluated as a variant to show the economic constraints on the selection of structural materials. The results of the analyses represent the integrated influences of different significant parameters on the achievement of minimum cost-dimension optimization. Besides, a well-known commercial geotechnical engineering software is used to compare the appropriateness of the suggested designs in terms of both the attainment of geotechnical stability and the structural requirements. Consequently, this study can guide both researchers and designers to select the proper and optimal sections of RC-retaining wall systems with simultaneous analyses of parameters that are influenced by the design process. Furthermore, the optimization results indicate that a significant cost reduction may be achieved when compared with the traditional pre-design method.
31
Boivin, Yannick, and Patrick Paultre. "Seismic force demand on ductile reinforced concrete shear walls subjected to western North American ground motions: Part 2 — new capacity design methods." Canadian Journal of Civil Engineering 39, no. 7 (July 2012): 738–50. http://dx.doi.org/10.1139/l2012-044.
Full textAbstract:
This paper proposes for the Canadian Standards Association (CSA) standard A23.3 new capacity design methods, accounting for higher mode amplification effects, for determining, for a single plastic hinge design, capacity design envelopes for flexural and shear strength design of regular ductile reinforced concrete cantilever walls used as seismic force resisting system for multistorey buildings. The derivation of these methods is based on the outcomes from a review on various capacity design methods proposed in the current literature and recommended by design codes and from the extensive parametric study presented in the companion paper. A discussion on the limitations of the proposed methods and on their applicability to various wall systems is presented.
32
Jamšek, Aleš, and Matjaž Dolšek. "The Reduced-Degree-of-Freedom Model for Seismic Analysis of Predominantly Plan-Symmetric Reinforced Concrete Wall–Frame Building." Buildings 11, no. 8 (August 21, 2021): 372. http://dx.doi.org/10.3390/buildings11080372.
Full textAbstract:
A reduced-degree-of-freedom (RDOF) model for seismic analysis of predominantly plan-symmetric reinforced concrete (RC) wall–frame buildings is introduced. The RDOF model of the wall–frame building consists of elastic beam–column elements with concentrated plasticity used for simulating cantilever walls and predominantly plan-symmetric RC frame buildings that are represented by the improved fish-bone (IFB) model. In this paper, the capability of the RDOF model is demonstrated for two frame buildings and two wall–frame buildings. The RDOF models were defined directly from the building information model. This is an advantage of RDOF models with respect to single-degree-of-freedom (SDOF) models, while the computational robustness of the RDOF models also makes them attractive for the seismic analysis of building stock. The imposed cyclic displacement analyses conducted for the investigated buildings proved that the condensation of the degrees of freedom for RDOF models was appropriate. Consequently, only minor differences were observed for maximum storey drift IDA curves, maximum storey acceleration IDA curves, and seismic fragility functions for different limit states. However, development is needed to make RDOF models appropriate for preliminary seismic performance assessment of plan-irregular buildings.
33
Kato, Daisuke, Daisuke Sato, and Tadashi Takamatsu. "Effects of opening location on flexural behavior of RC columns with sidewalls." Bulletin of the New Zealand Society for Earthquake Engineering 50, no. 4 (December 31, 2017): 547–54. http://dx.doi.org/10.5459/bnzsee.50.4.547-554.
Full textAbstract:
Practical use of secondary walls such as sidewalls is common because the contributions of secondary walls for stiffness or strength have been recognized. In 2016, “AIJ Standard for Lateral Load-carrying Capacity Calculation of Reinforced Concrete Structures” was published as a draft by Architectural Institute of Japan. In this standard new equations for columns with side walls were proposed. From this viewpoint, the authors have conducted static loading tests of flexurally controlled RC column specimens with single opening in the sidewall, to investigate the effects of openings on strength and deformation capacity of RC columns with a side walls. In this paper, the limitations on location of openings inside sidewalls to avoid their effects on flexural strength and deformation capacity are examined using design equations for flexural strength based on full plastic moment of the column and sidewall. The test results indicate that the proposed limitation line on location of openings to avoid their effects for flexure could be effective for practical design.
34
Su, Yi Sheng, Yue Chun Luo, Guo Liang Jiang, Jin Yun Quan, and Yi Shen. "Seismic Analysis of Fly Ash Plate Sandwich Polyurethane Insulation Composite Wall." Applied Mechanics and Materials 275-277 (January 2013): 1003–7. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.1003.
Full textAbstract:
In order to study the seismic stress performance of the reinforced concrete frame assembly fly ash plate sandwich polyurethane composite wall insulation system (FW). In this paper, 2 bay single-layer single-span hollow fly ash plate sandwich polyurethane in filled frames were tested under low cyclic horizontal loadings with different ratio of high to width and different stiffness frame . Based on the experiment, the damage process, failure mode, load carrying capacity are studied. The interaction between the fly ash plate sandwich polyurethane infill walls and the overall frame of constraint system are investigated. The results indicate that the bearing capacity has little related to height-width ratio of wall; sandwich polyurethane wall panels and frame has good integrity and energy dissipation capacity; the ratio of high to width smaller, ductility of wall is better . After study the failure pattern of the specimen, we know that the bearing capacity of fly ash powder polyurethane thermal insulation wall is not accord with formula of seismic shear of not bearing masonry.
35
Dashti, Farhad, Rajesh P. Dhakal, and Stefano Pampanin. "Blind prediction of in-plane and out-of-plane responses for a thin singly reinforced concrete flanged wall specimen." Bulletin of Earthquake Engineering 16, no. 1 (August 11, 2017): 427–58. http://dx.doi.org/10.1007/s10518-017-0211-x.
Full text
36
Akyildiz, Ahmet Tugrul, Alicja Kowalska-Koczwara, and Łukasz Hojdys. "Seismic Protection of RC Buildings by Polymeric Infill Wall-Frame Interface." Polymers 13, no. 10 (May 14, 2021): 1577. http://dx.doi.org/10.3390/polym13101577.
Full textAbstract:
This paper is aimed at investigating the usage of flexible joints in masonry infilled walls surrounded by reinforced concrete (RC) frames. For this purpose, a real-size specimen was numerically created and exposed to the seismic loads. In order to evaluate both in-plane and out-of-plane performances of the infill walls, the system was chosen as a box shaped three-dimensional structure. In total, three different one-story constructions, which have single bays in two perpendicular directions, were modeled. The first type is the bare-frame without the infill walls, which was determined as a reference system. The second and third types of buildings are conventional mortar joint and PolyUrethane Flexible Joint (PUFJ) implemented ones, respectively. The influence of these joints on the material level are investigated in detail. Furthermore, general building dynamic characteristics were extracted by means of acceleration and displacement results as well as frequency domain mode shapes. Analyses revealed that PUFJ implementation on such buildings has promising outcomes and helps to sustain structural stability against the detrimental effects of earthquakes.
37
Vervoort, P. "Lakehead terminal elevators: aspects of their engineering history." Canadian Journal of Civil Engineering 17, no. 3 (June 1, 1990): 404–12. http://dx.doi.org/10.1139/l90-044.
Full textAbstract:
Massive grain elevators have been a dominant feature of the waterfront at Thunder Bay since 1883 when the first terminal was under construction. The earliest terminal elevators built by the Canadian Pacific Railway were constructed in the wooden crib technique on a pile foundation. By the turn of the century, the inadequacies of the crib terminals forced engineers to experiment with new materials and new design concepts for terminal elevators. Steel, tile, and reinforced concrete all came into use for terminal elevator construction between 1898 and 1903. By 1910, the plan of the elevator had evolved from a single building into four separate structures. The appearance of the typical Lakehead terminal elevator today is the result of these engineering experiments which occurred at the end of the nineteenth century and in the early years of the twentieth. Key words: grain elevators, concrete construction, slip forms, formwork, bins, silos, timber construction, crib walls, cribs, steel construction.
38
Lee, Jaejoon, Hyunji Lee, Hongsik Yun, Chol Kang, and Moonsoo Song. "Improved Vulnerability Assessment Table for Retaining Walls and Embankments from a Working-Level Perspective in Korea." Sustainability 13, no. 3 (January 21, 2021): 1088. http://dx.doi.org/10.3390/su13031088.
Full textAbstract:
Climate change can lead to unpredictable slope collapse, which causes human casualties. Therefore, Korea has devoted significant effort to the management of slope disasters. The Ministry of the Interior and Safety of Korea, which oversees the safety of the nation’s people, has allocated a four-year budget of $557 million to investigate, assess, and maintain steep slope sites. However, there have been fatalities caused by steep slope site evaluations based on inadequate knowledge and a single retaining walls and embankments (RW&E) assessment table. Therefore, the assessment table for RW&E-type steep slopes needs to be improved in terms of its accuracy, simplicity, and ease of use. In this study, domestic and global evaluation methods were reviewed, problems associated with the existing RW&E assessment table were identified, and a focus group interview was conducted. The RW&E assessment table was improved through an indicator feasibility survey and analytic hierarchy processing. The improved assessment table was categorized from one to four classifications to reduce the ambiguity of the evaluation: concrete, reinforced soil-retaining walls, stone embankments, and gabions. This study will provide the sustainability of slope safety and serve as a reference for classification and evaluation criteria across all national institutions that conduct RW&E evaluations.
39
Singh, Harvinder. "Designing Laterally Loaded RC Stiffened Plates: Energy Balance Concept." ISRN Civil Engineering 2012 (November 14, 2012): 1–9. http://dx.doi.org/10.5402/2012/709157.
Full textAbstract:
Plates are most widely used structural systems to build and/or enclose the space along with some other structural elements, namely, walls, columns, and so forth. in any building. Design procedure for proportioning plates has been recommended in various design codes based upon empirical relations and some factors found on basis of the results of an extensive series of tests and well-established performance record of various plate/slab systems constructed in the past. These guidelines have a number of inherent limitations in the form of assumptions, thereby, forcing the designers to proportion the plate system within the domain of these limitations. A procedure to design reinforced concrete stiffened-plates is presented using an energy-balance concept and it can be used for both a single panel as well as multipanel rectangular plate system with any value of aspect ratio, number of panels, and orthotropy. To validate the results from the proposed design procedure, these are compared with the results from well-established literature on the plate analysis and are found to be in good agreement. Working procedure is illustrated with the help of design examples.
40
Vukobratović, Vladimir, and Sergio Ruggieri. "Floor Acceleration Demands in a Twelve-Storey RC Shear Wall Building." Buildings 11, no. 2 (January 25, 2021): 38. http://dx.doi.org/10.3390/buildings11020038.
Full textAbstract:
The seismic response of acceleration-sensitive non-structural components in buildings has attracted the attention of a significant number of researchers over the past decade. This paper provides the results which improve the state-of-knowledge of the influences that higher vibration modes of structures and nonlinearity of non-structural components have on floor acceleration demands. In order to study these influences, a response-history analysis of a code-designed twelve-storey reinforced concrete building consisting of uncoupled ductile cantilever shear walls was conducted. The obtained absolute floor accelerations were used as a seismic input for linear elastic and nonlinear non-structural components represented by simple single-degree-of-freedom systems, and the main observations and findings related to the studied influences along the building height are presented and discussed. Additionally, the accuracy of the method for the direct determination of peak floor accelerations and floor response (acceleration) spectra recently co-developed by the first author was once again investigated and validated. A brief summary of the method is provided in the paper, along with the main steps in its application. Being relatively simple and sufficiently accurate, the method (in its simplified form) has been recently incorporated into the draft of the new generation of Eurocode 8.
41
Semeniuk, Slavik Denisovich, and Yuriy Nikolayevich Kotov. "REINFORCED CONCRETE RETAINING WALLS." Вестник Белорусско-Российского университета, no. 4 (2018): 86–101. http://dx.doi.org/10.53078/20778481_2018_4_86.
Full text
42
Pavlov, Alexey, Larisa Pavlova, and Lyudmila Pavlova. "Multi-criteria thermal evaluation of wall enclosures of high-rise buildings insulated products based on modified fibers." E3S Web of Conferences 33 (2018): 02004. http://dx.doi.org/10.1051/e3sconf/20183302004.
Full textAbstract:
In article results of research of versions of offered types of heaters on the basis of products from the modified fibers for designing energy efficient building enclosures residential high-rise buildings are presented. Traditional building materials (reinforced concrete, brick, wood) are not able to provide the required value of thermal resistance in areas with a temperate and harsh Russia climate in a single-layered enclosing structure. It can be achieved in a multi-layered enclosing structure, where the decisive role is played by new insulating materials with high thermal properties. In general, modern design solutions for external walls are based on the use of new effective thermal insulation materials with the use of the latest technology. The relevance of the proposed topic is to research thermoinsulation properties of new mineral heaters. Theoretical researches of offered heaters from mineral wool on slime-colloidal binder, bentocolloid and microdispersed binders are carried out. In addition, theoretical studies were carried out with several types of facade systems. Comprehensive studies were conducted on the resistance to heat transfer, resistance to vapor permeation and air permeability. According to the received data, recommendations on the use of insulation types depending on the number of storeys of buildings are proposed.
43
Kovalenko, O. V. "MODERN HYDROACTIVE POLYURETHANE FOR RESTORATION OF WATERPROOFING CAPABILITY OF HYDROTECHNICAL STRUCTURES." Міжвідомчий тематичний науковий збірник "Меліорація і водне господарство", no. 1 (July 22, 2019): 108–16. http://dx.doi.org/10.31073/mivg201901-155.
Full textAbstract:
The main material of the hydrotechnical structures of the water management and reclamation complex is concrete. Its durability is the main indicator of reliability of building operation. The high density of hydraulic concrete, which determines the water resistance, is a guarantee of its durability. At the same time, in hydraulic concrete during the operation under the influence of aggressive environmental factors various defects (cracks, dissected zones)develop, which reduce its waterproofing capability. These defectsare the main centers of water filtration through building structures.
At first, drip filtration develops in buildings, which in the course of time increases into active jet filtration. That can lead to the complete destruction of the building. In this connection, the issue of restoration of monolithicity and waterproofing of concrete hydro-technical constructions is relevant. The solution of the problem may be the use of injection waterproofing of the structures when using hydroactive polyurethane resins. Due to the presence in the chain of macromolecules the final isocyanate (-NCO) groups, polyurethanes are capable for interacting with water molecules with the release of carbon dioxide, which leads to foaming. As a result, water blockage occurs in the concrete body and its waterproofing is restored.
The analysis of the modern construction market shows that there is currently a sufficiently wide range of single- and two-component hydroactive polyurethane resins capable of reacting with water with foam formation. As the study has shown, the rate of polymerization, the beginning and the end of polyurethane compositionsfoaming substantially depend on the rate of catalyst or polymerization accelerator in the composition, as well as on the environmental temperature. So,when increasing the rate of catalyst in the mixture from 2 to 9%, the rate of polymerization reaction increases by 3,3-3,9 times, and when increasing the environmental temperature from 10 to 25 °C, the polymerization rate increases in 1,3-1,4 times. The foaming time of polyurethane compositions varies within 0,8 ... 16 minutes. Depending on the polyurethane formulations, the resins can be slow- reactive, fast-reactive and ultrafast-reactive, which opens a prospect for their application in the conditions of the filtration of different intensity: from drip to jet.
Two-component polyurethane resins are the most promising for application in the technology of injection waterproofing on hydraulic engineering structures of water management and reclamation area, which enable to eliminate water leakage through the structures of different intensity: from drip to active jet filtration. Two-component polyurethane resins such as CarboPur, Tunnelinjekt, PenePurFoam, when contacting with water, form a rigid elastic foam with high physical and mechanical properties: bending strength up to 80 MPa, adhesion to water-saturated concrete to 2, 8 MPa.
Field study proved the high efficiency of injecting waterproofing with the use of hydroactive polyurethane resins in the conditions of water filtration through the structures of docking facilities of pumping stations. In the course of implementation of the projects on the restoration of waterproofing of reinforced concrete structures, the following types of work were performed: eliminating leaks through the isolation joints of concrete, as well as through shrinkage and structural cracks; eliminating leaks in the adjacent zones of "wall-floor", "wall-ceiling"; sealing leaks through the places of engineering communications laying(pipelines); arrangement of shut-off and veal waterproofing in the walls (injection of resins into dilapidated zones of the structure).
44
Thomas, Stency Mariam, and Prince Arulraj. G. "OPTIMIZATION OF SINGLY REINFORCED RC BEAMS." International Journal of Research -GRANTHAALAYAH 5, no. 2 (February 28, 2017): 199–207. http://dx.doi.org/10.29121/granthaalayah.v5.i2.2017.1724.
Full textAbstract:
The main objective of this paper is to achieve an optimal design for the reinforced concrete beams. Optimization of beams results in saving in cost. The objective function is to minimize the total cost of the beam. The cost of each beam includes the cost of concrete, reinforcement and formwork. The optimization process is done for different grades of concrete and steel to determine the best grade of concrete and steel. The optimal design is carried out using MATLAB's (The Mathworks, Inc.) software. Optimization problem is formulated as a Nonlinear constrained minimization problem. This was solved using the fmincon SQP Algorithm. Many problems were solved and it was found that the solutions give the most economical design.
45
D’Ambra, C., G. P. Lignola, and A. Prota. "Multi-Scale Analysis of In-plane Behaviour of Tuff Masonry." Open Construction and Building Technology Journal 10, no. 1 (May 31, 2016): 312–28. http://dx.doi.org/10.2174/1874836801610010312.
Full textAbstract:
Various methodologies are available today in engineering professional practice to analyse structures, in particular in the field of masonry structures. Many of the methods are derived from reinforced concrete frames but sometimes they suffer of lack of comprehensive experimental validation due to difficulties to simulate the many different kinds of masonries and they suffer from lack of critical comparison between them. In fact some methods seem to be able to provide accurate results, but are extremely expensive from a computational point of view and they require detailed material characterization and knowledge of actual geometry of the masonry and its constituents. However the usual uncertainty on the material mechanical properties and geometry details jeopardizes seriously the accuracy of the most refined analyses. Previous works by the authors remarked that nonlinear properties like as fracture energy, crucial for instance in the definition of post peak behaviour and ductility of masonry, have a crucial role at the single panel scale level analysis, while their impact is less and less crucial on the behaviour of entire walls and masonry structures. The aim of the overall work is to compare the most common methods of analysis for masonry from micro-scale to macro-scale, where not only geometrical refinement of the analysis is crucial, but also the number and details of required mechanical parameters. It is seen that macro-models are important to analyse large structures and the computational expense and required knowledge level are usually reasonable. To this scope a simple nonlinear material model for tuff masonry is proposed and results are compared between refined and simple models to simulate a tested real scale wall prototype with an opening.
46
Siregar, Atur P. N. "Experimental investigation of the flexural ductility of singly reinforced concrete beam using normal and high strength concrete." Journal of Sustainable Engineering: Proceedings Series 1, no. 2 (September 30, 2019): 218–24. http://dx.doi.org/10.35793/joseps.v1i2.30.
Full textAbstract:
This paper discusses and reports based on the experimental investigation of the flexural ductility of singly reinforced normal strength and high strength concrete beams. Compressive concrete strength of 40 and 95 MPa were employed to create singly reinforced normal strength and high strength concrete beams, respectively. Fourteen samples made of normal and high strength concrete were engaged to observe the flexural ductility behaviour of beams on the basis of four point bend testing. Analysis on the basis of the flexural cracking, ultimate failure and curvature ductility were carried out to derive the comparison of singly reinforced normal strength and high strength beams. The beams using high strength concrete revealed a higher ductility ratio than that of normal strength concrete, i.e. 4.50 for high strength concrete and 2.60 for normal strength concrete.
47
Mahzuz, H. M. A. "Performance evaluation of triangular singly reinforced concrete beam." International Journal of Structural Engineering 2, no. 4 (2011): 303. http://dx.doi.org/10.1504/ijstructe.2011.042896.
Full text
48
Olawale, SOA, and OP Akintunde. "Fuzzy Logic Design Approach for A Singly Reinforced Concrete Beam." Journal of Civil Engineering Research & Technology 3, no. 1 (March 31, 2021): 1–3. http://dx.doi.org/10.47363/jcert/2021(3)111.
Full textAbstract:
This paper presents the Fuzzy logics approach for a singly reinforced concrete beam. The rules are generated for the FIS for the variables. The width, and the moment constitutes the crisp data for the inputs and the steel ratio represents the crisp output. The MATLAB fuzzy tool kit is used to execute the simulation. The code prescription of the design of a singly reinforced concrete beam is a straight forward calculation. However, the overestimation of reinforcement can be enormous. This can be very impacting on the cost of the project. This work attempts to use fuzzy logic predictive power to design a singly reinforced concrete beam. The result reasonable agreement between the code provisions and the fuzzy logic predictions. It was established that fuzzy logic can be adopted as a significant technique for the optimization of the design of a singly reinforced concrete beam.
49
Nikolaev, V. B., S. Ya Gun, S. E. Lisichkin, and O. B. Lyapin. "Strength of reinforced-concrete retaining walls." Hydrotechnical Construction 22, no. 10 (October 1988): 616–21. http://dx.doi.org/10.1007/bf01429034.
Full text
50
Sengupta, Piyali, and Bing Li. "Hysteresis Behavior of Reinforced Concrete Walls." Journal of Structural Engineering 140, no. 7 (July 2014): 04014030. http://dx.doi.org/10.1061/(asce)st.1943-541x.0000927.
Full text