水化热抑制剂和氧化镁对水工自密实混凝土性能的影响

研究了掺加水化热抑制剂和(或)氧化镁的水工自密实混凝土工作性能、抗压强度、绝热温升、自生体积变形等性能发展规律。结果表明,外掺5%氧化镁对水工自密实混凝土抗压强度影响不大,掺有1%水化热抑制剂的水工自密实混凝土早期成熟度低,后期抗压强度与空白样相差无几。氧化镁的掺入使得水工自密实混凝土的最终绝热温升值略有增加,单掺水化热抑制剂混凝土早期绝热温升值较不掺抑制剂的水工自密实混凝土低约(10~20)℃,10d后与空白样相差不大。外掺氧化镁的水工自密实混凝土360d自生体积变形值可达147×10-6且依旧保持继续膨胀趋势,相比于单掺氧化镁混凝土,复掺氧化镁和水化热抑制剂混凝土的自生体积变形值约有15%的下降。

Influence of Hydrothermal Inhibitor and Magnesium Oxide on the Performance of Hydraulic Self-compacting Concrete

The performance including workability, compressive strength, autogenous volume deformation and adiabatic temperature rise development of hydraulic self-compacting concrete containing hydrothermal inhibitor and (or) magnesium oxide were investigated. The results show that the addition of 5% magnesium oxide has little influence on the compressive strength of hydraulic self-compacting concrete. The early maturity of hydraulic self-compacting concrete mixed with 1% hydrothermal inhibitor is low, and the later compressive strength is almost the same as that of blank sample. The adiabatic temperature rise of hydraulic self-compacting concrete containing magnesium oxide increased slightly. Compared with blank sample, the adiabatic temperature rise in early stage of hydraulic self-compacting concrete mixed with 1% hydrothermal inhibitor is lower than about 10~20 degrees centigrade, and the difference is not significant after 10 d. The autogenous volume deformation value of hydraulic self-compacting concrete with magnesium oxide can reach 147×10-6 at curing stage of 360 d, and it still keeps the expansion trend. Compared with self-compacting concrete adding magnesium oxide, the autogenous volume deformation of hydraulic self-compacting concrete complicated with magnesium oxide and hydrothermal inhibitor decrease by about 15%.