搅拌时间对掺减水剂混凝土强度均匀性的影响

Effect of Mixing Time on Strength Uniformity of Concrete with Polycarboxylic Superplasticizer

通过测定不同搅拌时间下C30、C40、C50混凝土不同部分的强度分布,探讨了搅拌时间对掺聚羧酸减水剂混凝土强度均匀性的影响。结果表明:搅拌时间过短使混凝土拌合物中胶凝材料分散不匀,混凝土强度低;适当延长搅拌时间使组成材料分散均匀,提高混凝土的密实度和强度;过长的搅拌时间降低拌合物的和易性,增大含气量,降低混凝土的密实度和强度。本试验配制的掺西卡减水剂的C30、C40和C50混凝土的合适的搅拌时间为75 s～90 s。

The influence of mixing time on the strength uniformity of concrete mixed with polycarboxylic superplasticizer is discussed by measuring the strengths of different parts of C30,C40 and C50 at different mixing times.When the mixing time is too short,the cementitious materials in the concrete mixture can’t be well dispersed,which results in the strength of concrete is low.Proper mixing time should make the component materials evenly distributed,which improves the density and compressive strength of concrete.Excessive mixing time reduces the workability of the mixture and increases the air content,which decreases the compactness and compressive strength of concrete.The suitable mixing time for C30,C40 and C50 mixed with Concrete Admixtures by Sika is 75 s^90 s.