摘要
混凝土从搅拌站生产出来后,需经过一段间歇时间(运输时间、等候时间、浇筑时间)后,才能浇筑到工程结构部位。如果是浇筑墙体,间歇时间可能会达到4～5 h,间歇时间的延长可能会影响混凝土的使用性能。通过对不同强度等级混凝土试验,研究间歇时间对混凝土工作性及抗压强度的影响。结果表明在使用聚羧酸外加剂时,为保证混凝土拌合物的工作性,外加剂的二次加入量随着间歇时间的延长而增加,混凝土强度等级提高,外加剂的二次加入量随之增大;成型时间在4～5 h以内时,各强度等级混凝土的抗压强度无明显下降;混凝土加水调整前,各时间段成型的混凝土抗压强度变化不明显,加水调整后,混凝土各龄期抗压强度明显下降。
There have a intermittent time（transportation time, waiting time, pouring time ） before the concrete pouting into the area of engineer- ing structures, atter prdouct it from mixing station.The intermittent time will be reached 4-5 hours if pouring wall, that may influence the worka- bility of concrete with the prolongation of time.Through the concrete test with different strength grade, research the impact of＇concrete intermittent time on workability and compressive strength.The results shown that when used polycarboxylate admixture,to ensure the workability of concrete, the second time admixture adding amount will be increased with time or concrete strength grade increased;There is no significant decline in com- pressive strength with different strength grade concrete, when the forming time in 4~5 hours;concrete compressive strength did not change signifi- cantly before adding water, and decreased significantly in each age after adding water.
出处
《混凝土》
CAS
CSCD
北大核心
2012年第7期99-101,共3页
Concrete
关键词
混凝土间歇时间
和易性
抗压强度
影响
concrete intermittent time
worl（ability
compressive strength
influence
