Synthetic polymer latexes, such as styrene–butadiene rubber (SBR) latex addition in Portland cement has gained wider acceptance in many applications in the construction industry. Polymer-modified cementitious systems seals the pores and micro cracks developed during hardening of the cement matrix, by dispersing a film of polymer phase throughout the concrete. A comprehensive set of experimental test were conducted for studying the compressive properties of SBR latex polymer with crimped polypropylene fibres at relative volume fractions of 0.1 and 0.3%. The results indicated that the addition of polypropylene fibre has little effect on the reduction in the workability of concrete composite containing fly ash and SBR Latex. Increase in polypropylene fibres upto 0.3% Vf showed increase in compressive strength upto 57.5 MPa. The SBR concrete without fibre showed an increase in strength upto 20% compared to plain concrete. Test results also indicated that the compressive strength was increased in SBR fibre concrete by means of an ordinary dry curing process than wet curing because of their excellent water retention due to polymer film formation around the cement grains. On the contrary the compressive strength reduces for SBR fibre concretes under wet curing compared to dry curing.
This study explores the influence of alkali activators on the initiation of polymerization reaction of alumino-silicate minerals present in class-F fly ash material. Different types of fly ash aggregates were produced with silicate rich binders (bentonite and metakaolin) and the effect of alkali activators on the strength gain properties were analyzed. A comprehensive examination on its physical and mechanical properties of the various artificial fly ash aggregates has been carried out systematically. A pelletizer machine was fabricated in this study to produce aggregate pellets from fly ash. The efficiency and strength of pellets was improved by mixing fly ash with different binder materials such as ground granulated blast furnace slag (GGBS), metakaolin and bentonite. Further, the activation of fly ash binders was done using sodium hydroxide for improving its binding properties. Concrete mixes were designed and prepared with the different fly ash based aggregates containing different ingredients. Hardened concrete specimens after sufficient curing was tested for assessing the mechanical properties of different types concrete mixes. Test results indicated that fly ash -GGBS aggregates (30S2‒100) with alkali activator at 10M exhibited highest crushing strength containing of 22.81 MPa. Similarly, the concrete mix with 20% fly ash-GGBS based aggregate reported a highest compressive strength of 31.98 MPa. The fly ash based aggregates containing different binders was found to possess adequate engineering properties which can be suggested for moderate construction works.