PAE-modified mortars

WATER IMMERSION PERIOD, hours PAE-MODIFIED MORTAR... 

Generally, the latex-modified mortars provide the high retention of flexural strength. SBR-and PAE-modified mortars have a higher weatherability than the other latex-modified mortars. 

The reduction in porosity, decreased water content, and air entrainment that results when latexes are used in mortar and concrete mixes make them much more resistant to freezing and thawing conditions than conventional mortar and concrete. Figure 6.17 presents the freeze-thaw durability in water (-18 to 4°C) of combined water-and dry-cured SBR-, PAE- and EVA-modified mortars [98], The frost resistance of mortars made with these latexes is markedly improved even at polymer-cement ratios of 5%. However, an increase in the polymer-cement ratio does not necessarily produce further improvement in freeze-thaw resistance. EMM and EMC, when exposed to outdoor conditions involving freeze-thaw, UV radiation and carbonation show better weatherability when compared with conventional mortar and concrete. 

COMPRESSIVE STRAIN xIO" COMPRESSIVE STRAIN,xIO COMPRESSIVE STRAIN, xlO- S -MOofFlIb PAE-MODIRED MORTAR EVA-MODIFIED MORTAR... 

Conflicting data exist on the creep behavior of latex-modified mortar and concrete. The creep characteristics of SBR- and PAE-modified concretes reported by Ohamal l are represented in Fig. 4.40. Like ordinary cement concrete, the relationships between loading time (t) and creep strain (ec) or creep coefficient (< )) (i.e., creq) strain/elastic strain ratio) of the latex-modified concretes fit approximately the expression ... 

The thermal resistance of latex-modifled mortar and concrete is governed by the nature, especially glass transition temperature of polymers used, polymer-cement ratio, and heating conditions, and ultimately by the thermal degradation of the polymers. Figure 4.59f l indicates the thermal resistance of SBR-, PAE-, and EVA-modified mortars at 100 to 200°C. The flexural strength of most latex-modified mortars at 100°C tends to initially... 

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