超缓凝剂SRA的研制与应用研究

Study on the research and application of Super Retarder Agent(SRA)

以蔗糖为主要原料研制出一种超效缓凝剂(简称SRA);并着重进行了SRA对水泥水化进程、凝结硬化、强度发展的影响试验,同时进行SRA作水泥稳定粒料路面基层延迟成型剂的应用试验.试验结果表明:(1)当SRA掺量为0.045%时可将终凝时间延长到10h;合理掺量的SRA能明显延缓水泥的早期水化,对强度发展无不利影响;SRA掺量过大(达0.48%)会促进凝结并影响强度形成.(2)SRA用作水泥稳定粒料路面基层的延迟成型剂的最佳掺量在0.05%～0.06%;用SRA可降低因延迟压实对水泥稳定粒料基层的强度和干密度的影响,可把延迟成型时间延长到9h;在成型延迟4h,6h,9h后,掺入SRA的水泥稳定粒料的强度和干容度损失明显小于未掺外加剂的混合料在相同延迟成型条件下的强度损失.(3)在延迟成型时间比较长时,SRA比木钙具有更为明显的延迟成型效果,且具更明显的技术经济性.

a new type of super retarder agent （SRA） was made from cane sugar; Test for influence of SRA on hydration process, setting and hardening and strength development of cement was carried out, the test also studied the application of SRA being as forming time delay agent of cement-treated base .the test proved that： （1） final setting time delay may be increased to 10h when mixing ratio of SRA at 0.045%; early hydration of cement time delay may be increased greatly by SRA at rational mixing ratio, there＇s no influence on strength development; While too high ratio of SRA （ up to 0.48%） admixture may progress setting and influence the strength forming. （2） optimal mixing ratio of SRA as delay forming agent in cement treated base is 0.05%-0.06%; the influence of compacting delay on strength and dry density of road base may be reduced by SRA additive, forming time may be delayed to 9h; after the forming time is delayed to 4h, 6h and 9h, the strength and dry density shrinkage of cement-treated base with SRA admixture are much less than that of those without SRA. （3） when the delay in forming time is rather long, SRA will be of more remarkable retarding effect than retarder made from wood , and it is more economic.