Kirill Polozhiy

Pore System and Hydric Properties of Two Different Lime Plasters with Finely Crushed Brick

Two different lime plasters with finely crushed brick are studied in this article. In the first plaster the pozzolan mixture was used as silica sand while in the second it was dosed as replacement of the lime substitute and silica sand (the substitution levels being 20% and 50%). Classic lime plaster was used as a reference material. Studied parameters were basic physical properties (measured by water vacuum saturation and by helium pycnometry), characterization of pore system (by mercury porosimetry) and transport of liquid water.

Low Cost Cement Floor Screed

Floor screed with different amount of pozzolanic admixture was studied. There were designed 3 mixtures with different amount of the pozzolana. The basic physical properties, mechanical properties and frost resistance were determined. The water /cement coefficient was decided to be taken according to the consistence of the mortar. The mixtures were designed with respect to their application as screed. The properties of developed low-cost pozzolanic screed exceeds the reference material.

Pore Structure and Hydric Characteristics of Renders with Blended Binder

Exterior renders are protecting the load bearing parts of building constructions against the negative action of surrounding environment such is freezing-thawing action, crystallization of salts in pore system of material, biocorrosion etc. Thus sufficient mechanical properties, namely bending strength and adhesion to load bearing material’s surface, as well as durability properties are required. The paper deals with durability parameters of lime plasters modified by pozzolana and small amount of Portland cement. Such modification provided reduction of rate of liquid water transport what is promising with respect to freezing-thawing resistance of render. The water vapour diffusion coefficient was influenced just moderately.

Influence of Plasticizer on Properties of Blended Cement Concrete

In this article Portland-slag cement was step by step replaced with pozzolana (fine red-clay ceramics) in concrete. This is first step of research that is why the only measured characteristics were consistency of mixtures and compressive strength. There were designed four mixtures with increasing replacement of Portland cement by 10 % each (CR, C1, C2, C3) where complete activity of pozzolana was assumed. Mixtures C4, C5 and C6 were designed with respect to presumed just partial activity of the used pozzolana (set as 40 %). The water/cement coefficient was decided to be taken according to the consistence of the mortar.

Treated Coconut Coir Pith as Component of Cementitious Materials

The presented paper deals with utilization of raw and treated coir pith as potential component of cementitious composites. The studied material is coir pith originating from a coconut production. Its applicability as cement mixture component was assessed in terms of the physical properties of concrete containing different amount of coir pith. Basic physical properties, compressive and bending strength, and hygric transport characteristics as well as thermal properties belong among the studied characteristics. It was proved that the concrete with 5% (by mass of cement) of this waste material shows appropriate physical properties and it gives rise to an applicable material for building structures. Generally, the coir pith can be regarded as lightening additive. When 10% of coir pith was added, it has led to higher deterioration of properties than what is acceptable since such dosing is greatly increasing the total porosity. The influence of chemical treatment of coir pith was evaluated as well; both tested treatment methods improved the performance of cementitious composites while the acetylation was somewhat more effective the treatment by NaOH.