膨胀剂对大掺量矿物掺合料混凝土水化和收缩性能的影响

Influence of expansive agent on hydration and shrinkage properties of concrete with high content mineral admixture

用膨胀剂等量替代基准混凝土中的部分粉煤灰,研究不同养护条件下,膨胀剂对大掺量矿物掺合料混凝土强度、水化和收缩性能的影响。结果表明:掺加UEA膨胀剂可使混凝土抗压强度有所降低,使胶凝材料的水化速率增大、水化温升提高、最高温耗时缩短和水化放热量增大。掺加UEA膨胀剂不能有效改善混凝土的干燥收缩和限制膨胀率。膨胀剂种类和掺量对混凝土自生体积变形的影响较大,同掺量的氧化镁复合膨胀剂好于UEA膨胀剂。

In this paper,the effect of expansive agent on the strength,hydration and shrinkage of concrete with high content mineral admixture under different curing conditions was studied by replacing part of fly ash in benchmark concrete with expansive agent.The results show that the compressive strength of concrete can be reduced by adding UEA expansion agent,the hydration rate and temperature rise of cementitious materials can be increased,the time of maximum temperature can be decreased and the release of hydration heat can be increased.Adding UEA expansion agent cannot effectively improve the drying shrinkage and limiting expansion rate of concrete.The type and content of expansive agent have great influence on the autogenous volume deformation of concrete.The magnesium oxide composite expansion agent with the same content is better than UEA expansive agent.