Littérature scientifique sur le sujet « Vápenná malta »

The theoretic part of this diploma thesis interprets historical procedures of lime mortar manufacturing and modern options for the historical lime plaster renovation. The experimental part of this diploma thesis aims for the comparison of physical-mechanic characteristic of lime mortar manufactured with different kinds of lime. The main goal is verifying of positive influence of using the aged lime mortar on its physical-mechanic characteristics.

Natural pozzolanic materials played an important role in Ancient architecture. In the last decades and nowadays it is artifical pozzolan which especially finds its use as an additive to mortar and concrete to improve some, especially the mechanical properties. This master thesis deals with study of pozzolan type of fine brick powder which is a by-product of the production of calibrated bricks. Along with studying pozzolanic activity of brick powder, lime mortar with different proportions of brick powder as an additive or replacement of lime dust are investigated. What is observed is its impact on the consistency of these mortar, water absorption, strength in time or fracture-mechanical parameters of mortar. The results may indicate the possible potential use of this source of pozzolanic admixture in lime mortar and plaster which are nowadays mainly used for the restoration of facades of historic buildings.

The doctoral thesis deals with the reactivity of burnt clays in connection with modified lime mortars. The theoretical part of the doctoral thesis provides an overview of the properties of lime mortars, their quality and ways of their degradation. The different types of burnt clays (brick powder, bentonites and burnt clay shale), their origin, properties and factors affecting their reactivity and methods of its evaluation are stated. The properties and reactivity of burnt clays are evaluated on the basis of determination of pozzolanic activity, mineralogical and chemical composition, surface area, density, content of the amorphous phase and granulometry in the experimental part of the doctoral thesis. The compositions of lime mortars containing burnt clays and evaluation of an impact of burnt clay on the properties of mortars in the fresh and hardened state are given. Consistency, bulk density, workability and air content of mortars in the fresh state are evaluated. Strength characteristics depending on the time, water absorbability, porosity, capillary attraction, adhesion, coefficient of diffusion resistance, frost resistance, shrinkage, mineralogical composition and microstructure of mortars in the hardened state are evaluated. Attention is also paid to the influence of the cellulose ether addition into the modified lime mortars.

The thesis is focused on the comparison of the role of different types of aggregates and the binder-aggregate ratio on the properties of lime mortars. The theoretical part of the thesis deals with the effect of properties of aggregate, a binder-aggregate ratio and a use of calcareous aggregate, especially limestone, on the properties of mortars. It also deals with the utilization of limestone as aggregate in a history of masonry. In the practical part of the thesis there is a comparison of physically-mechanical and microstructural properties of mortars prepared with different type of aggregate (siliceous sand and limestone aggregate), with varying binder-aggregate ratio and also with a partial substitution of the aggregate by limestone fines. It was found that the usage of limestone instead of quartz sand produces the mortar of comparable properties. The partial substitution of the aggregate with limestone fines caused noticeable growth of strength, especially in mortars with higher binder-aggregate ratio.

Diploma thesis gives a brief description of the traditional technology of preparation of lime mortars for restoration of historical buildings. The theoretical part is focused on the preparation of lime mortars traditional methods, using appropriate materials for making and influence amount of water. Attention is also paid to the events that take place in the setting and hardening of lime mortar. In the experimental part of the research was conducted, which aimed to assess the influence of water-cement ratio and mixing ratio (binder to filler) on the properties of lime mortars. At various times were measured mechanical properties, density, shrinkage, frost resistance and porosity. The mortar was also carried out thermal analysis and found to contain calcium carbonate. Acquired knowledge could help in the reconstruction of historical buildings.