This paper describes the use of cement‐based waterproofing screed and coating, in which 10% original amount cement was replaced by fly ash 2% crystallization admixture added weight cement, as a mean protection concrete against aggressive environments. The modified materials were applied to underlying subjected testing physical mechanical properties after exposure effects environments for up 18 months. results analysis have shown that application materials, there is sufficient development...

The paper describes how a crystalline additive influences the properties of cement- based composites. investigation was focused on degradation mortars with exposed to selected aggressive environments. specimens were tested for compressive and flexural strength. influence microstructure is also discussed (high pressure mercury intrusion porosimetry, SEM, DTA). results confirmed positive values strength after exposure all

The paper focuses on the study of durability cement mortars made with secondary crystallization additives. It investigates influence crystalline additives degradation process exposed to gaseous CO 2 and freezing cycles. specimens were tested for compressive flexural strength at following ages after being treated by curing techniques: 28 days, 180 days 25 cycles, in . In order explain obtained results gain new information about microstructure studied, SEM sampling RDA analysis performed....

The paper focuses on examining the properties of mortars in which secondary crystallization (crystalline additive) was used. Laboratory tests have found that effect is influenced by conditions specimens been stored during first 28 days. investigation focused physical-mechanical and microstructure mortar containing a crystalline additive polypropylene fibres at different levels humidity for influence strength studied as well results show additives improves 28-day mortars.

The pore structure of a material radically infuences its properties, such as strength, freeze-thaw resistance, capillarity or resistance to elevated temperatures. character the is also limiting for intrusion aggressive oxides into material, which affects service life. paper describes how crystalline additive influences cement mortars. It effect secondary crystallisation and influence additon PP fibers on apparent porosity internal mortar. discusses conditions mortar’s structure.

Abstract The paper presents research into the changes of properties in cement-bonded particleboards caused by moisture saturation over course 504 h. Three particleboard variants were tested, all at age 18 months. first is a standard production-line board manufactured CIDEM Hranice, a.s. (identified as CP-R). other two modified by-products manufacturing process—dust (CP-D) and particulate mixture (CP-P). experiment observed boards’ dimensions, volume, mass. effect on their basic material was...

In production of AAC the fly ash was used as a source SiO 2 for many years. Now, after introducing selective non-catalytic reduction (SNCR) technology to coal combustion process, contain ammonia in form soluble salts, such NH 4 HSO and (NH ) SO , which causes problems during manufacturing AAC. Among all influence ions phase composition final product not fully described. The main aim this contribution is describe morphology autoclaved aerated concrete (AAC). For preparing laboratory...

This paper is focused on the effect of treatment fly ash after selective non-catalytic reduction (SNCR) with tannin autoclaved aerated concrete (AAC) production in order to reduce or stop ammonia leakage from fresh mixture due its alkalinity. A pure form and a tannin-based product „Farmatan“ were used as dosage ranging 0,5 g – 3 agent per 1 kg ash. Efficient was determined at 2 wt.% by speed an indicator change gaseous diluted water. The rheological properties mixtures observed consistency...

After introducing SNCR in coal combustion process power plants, the valuable by-product such as fly ash remains contaminated with amount of ammonia form NH 4 HSO , (NH ) 2 SO respectively, which became undesirable AAC technology because toxic is released air during mixing process. This paper deals effect varying content after selective non-catalytic reduction (SNCR) on physical-mechanical properties based autoclaved aerated concrete (AAC) main focus determination impact various ammonium ion...

Autoclaved aerated concrete (AAC) is, mainly in Europe, widely used construction material. It has an optimal combination of bulk density, strength and thermal conductivity coefficient for load-bearing non-load-bearing structures civil facilities. The production technology is based on a mixture ground silica sand, lime, cement, gypsum, aluminium powder additives. grinding sand most often carried out wet way, the sludge consequently technology. aim experiment was verification effect partial...

This paper deals with the use of computed tomography (CT) images and analytical software for nondestructive evaluation texture autoclaved aerated concrete (AAC) 20% fluidized bed combustion fly ash as a substitute quartz sand. The samples AAC, made in laboratory same composition but different ways curing fresh stage (before autoclaving), were subjected to observation differences silicate matrix, such inhomogenity, defects, pore size distribution. conditions limited drying resulted formation...

The paper describes an investigation into the influence of a crystalline additive on sulphur dioxide resistance cement-based composites. Cement mortars made with assistance secondary crystallization were exposed to aggressive environment and tested for ways how (CA) influences their degradation. results indicate that improved composites attack.

Abstract Due to the legislative regulations on NO x emissions, a selective non-catalytic reduction (SNCR) technology had been introduced coal combustion process in power plants. The valuable by-product, fly ash, contains ammonia form of soluble salts, e.g. NH 4 HSO and (NH ) 2 SO . After mixing SNCR ash with cement, thanks rise pH, toxic releases contaminates working area, so presence these salts is undesirable an autoclaved aerated concrete (AAC) manufacturing process. A possible solution...