氧化钙-硫铝酸钙复合膨胀剂在高性能混凝土中的应用技术研究

Study on the Application of Calcium-oxide Calcium Sulphoaluminate Composite Expansion Agent in High Performance Concrete

本文研究了新型氧化钙-硫铝酸钙复合膨胀剂的膨胀性、流变性和安定性。结果表明:新型膨胀剂在水泥压蒸安定性方面表现出良好的体积稳定性,安全掺量可提升至12%。在5%的掺量下,7d水泥胶砂试件限制膨胀率9.5×10-4,可有效抑制高性能混凝土的自收缩,补偿干燥收缩。该膨胀剂的掺入会降低新拌混凝土的流动性,但不会影响混凝土基体的密实性;且对混凝土抗压强度影响不大,适宜的膨胀剂掺量会增大混凝土的抗压强度,而当膨胀剂掺量过大时,则有可能使混凝土抗压强度略微降低。

The swelling,rheology and stability of a new type of calcium calcium sulphoaluminate expansion agent were studied in this paper. The results show that the new type of expansive agent has good volume stability in the autoclave stability. Safe dosage can be increased to 12%. The limit expansion rate of 7 day cement mortar specimen is 9. 5 × 10-4under the 5% dosage which can effectively restrain the self shrinkage of high performance concrete and compensate the shrinkage.The expansion agent can reduce the fluidity of fresh concrete and has little effect on the compactness and compressive strength of concrete. compressive strength of concrete is increased with appropriate amount of expansion agent. It is possible to reduce the compressive strength of concrete slightly when the amount of expansion agent is too large.