Influence of SBR latex and HPMC on the cement hydration at early age

Abstract

A study was carried out, using heat flow calorimetry, XRD, FTIR and SEM imaging analysis, of different influences which were exerted by the type of polymer, on the hydration behaviors of cement pastes. It is shown that both styrene-butadiene rubber latex (SBR latex) and hydroxypropylmethyl cellulose (HPMC) can cut down the cement hydration heat evolution rate and total heat between 5 h and 20 h. The former has a weaker influence but can play a positive role in enhancing the latter. XRD and FTIR analysis show that SBR latex and HPMC have played a negative role on the contents of Ca(OH)2 in cement pastes cured for 24 h, and there is a relationship of mutual promotion between SBR latex and HPMC in terms of inhibiting the formation and growth of Ca(OH)2, but this inhibiting effect becomes weaker at 72 h. HPMC has the superior inhibiting effect owing to its special OH groups compared to SBR latex.

Keywords

• Styrene-butadiene rubber
• Hydroxypropyl methyl cellulose
• Cement hydration
• Retardation