高效减水剂对结构混凝土长期性能影响

研究了聚羧酸(PCA)、高浓、低浓萘系(H-PNS,L-PNS)3种高效减水剂对混凝土浆体初始流动度、抗压强度及碳化、氯离子渗透扩散系数、干湿循环破坏性能影响.结果表明,PCA高效减水剂与H-PNS,L-PNS高效减水剂相比,具有掺量低、混凝土坍落度保持性好、早期强度发展快的特点.掺加3种高效减水剂混凝土中,相同碳化时间里,掺加L-PNS减水剂混凝土碳化深度>掺加H-PNS减水剂混凝土碳化深度>掺加PCA减水剂混凝土碳化深度,掺加L-PNS减水剂的混凝土氯离子渗透扩散系数>掺加H-PNS减水剂的混凝土氯离子渗透扩散系数>掺加PCA减水剂的混凝土氯离子渗透扩散系数.掺加3种高效减水剂的混凝土受干湿循环劣化损伤(相对抗压强度比、相对动弹性模量、质量损失)影响不大.

The Influence of Superplasticizer on Long-term Behavior of Structural Concrete

The influence of three types superplasticizers,i.e,polycarboxylic(PCA)、high and low concentration sulfonated naphthtalene-formaldehyde condensate(H-PNS,L-PNS),on the fluidity,compressive strength and long-term behavior(carbonation、chloride corrosion、drying-wetting cycles)of concrete was studied.The result showed that PCA superplasticizer has better fluidity preservation and higher compressive strength of concrete than H-PNS and L-PNS superplasticizer,the carbonation depth,chloride ion diffusion coefficient of concrete with three types superplasticizer are L-PNS>H-PNS> PCA,concrete with PCA superplasticizer has a resemble behavior to H-PNS,L-PNS superplasticizer under drying-wetting cycle(the weight lost、the relative compressive strength、the relative dynamic of elasticity).