镁渣矿粉复合对混凝土早期抗裂的影响研究

针对镁渣利用率低,以及对现代混凝土尺寸稳定性要求高的问题,以镁渣掺量,矿粉取代率为因素,设计正交试验方案,试验研究镁渣矿粉复合混凝土的早期抗裂性。结果表明:混凝土的水分蒸发率、单位面积的裂缝数目和总开裂面积均随矿粉取代率的增加近似线性增大,随镁渣掺量的增加呈非线性减小。镁渣掺量0~20%时,减小幅度大,镁渣效应高;镁渣掺量20%~40%时,减小幅度小,镁渣效应低。混凝土的总开裂面积与水分蒸发率有很好的线性相关性。矿粉对混凝土的早期抗裂不利,镁渣能有效补偿和抑制混凝土的早期开裂,保水性好是其提高混凝土早期抗裂性的重要机制。

Effect of magnesium slag and slag composite on early crack resistance of concrete

In view of the problem of low utilization rate of magnesium slag and high size stability requirement of modern concrete, taking magnesium slag content and slag replacement rate as factors, orthogonal test scheme was designed to study the early crack resistance of concrete with magnesium slag and slag by experiment. Results showed that: water evaporation rate, number of cracks and total crack area linearly increase with the increase of slag replacement rate, nonlinearly decrease with the increase of magnesium slag content, magnesium slag content of 0-20%, reduce greatly, the effect of magnesium slag is high, magnesium slag content 20-40%, a small decrease, magnesium slag effect low; total crack area and water evaporation rate of concrete has a good linear correlation. Slag on concrete early crack resistance adverse, magnesium slag can effectively compensate and inhibit early crack of concrete, good water retention is an important mechanism to improve the early crack resistance of concrete.