不同外掺料对机制砂混凝土强度及和易性影响分析

Analysis on strength and workability of manufactured sand concrete with different admixtures

分别采用矿粉、膨润土、偏高岭土取代部分水泥掺入到混凝土中,研究不同外掺料对机制砂混凝土和易性及抗压强度的影响。结果表明,掺入矿粉后,机制砂混凝土的流动性和粘聚性均提高;随着矿粉掺量的增加,机制砂混凝土的抗压强度先提高后降低,在矿粉掺量为10%时抗压强度最高。掺入膨润土后,机制砂混凝土的流动性、粘聚性和抗压强度均降低,和易性变差。掺入偏高岭土后,机制砂混凝土的坍落度、扩展度迅速降低,拌合物变得较为粘稠,工作性变差,但抗压强度迅速提高,偏高岭土掺量为20%时,机制砂混凝土的28d抗压强度较未掺偏高岭土的提高56.8%。

By adding mineral powder,bentonite and metakaolin into the concrete to replace part of the cement,effect of different admixtures on workability and compressive strength of manufactured sand concrete were studied. The test results show that the fluidity and cohesion of manufactured sand concrete are enhanced after adding mineral powder. With the increase of mineral powder content,the compressive strength of manufactured sand concrete increases first and then decreases. When the mineral powder content is 10%,the compressive strength of concrete reaches the maximum. After adding bentonite,the fluidity,cohesiveness and compressive strength of machine-made sand concrete decreased,and the concrete flexibility become worse. With the addition of metakaolin,the slump and expansion of manufactured sand concrete decrease rapidly,the concrete mixtures become more viscous,and the workability of concrete becomes worse. However,the compressive strength of concrete increases rapidly after adding metakaolin. When the content of metakaolin is 20%,the 28-day compressive strength of manufactured sand concrete increases by 56.8%.