C70自密实钢管混凝土材料配制技术

Mixing technology of C70 self-compacting steel tube-confined concrete

提高核心混凝土的强度是提高钢管混凝土承载力的重要途径。配制C70高强自密实钢管混凝土材料满足钢管混凝土的施工条件和性能要求:早期强度高,3 d抗压强度达到28 d的86.3%;工作性能优良,抗分离性能好,垂直浇筑4 m高钢管混凝土柱,各组分均匀分布;弹性模量不低于振实混凝土,为4.6×104 MPa;能产生足够的膨胀,360 d的自由膨胀率为6.9×10-4。

It is an important approach for improving carrying capacity of steel tube-confined concrete to improve strength of core concrete.The core concrete whose compressive strength is 70 MPa can meet the need of engineering requirements.First, the compressive strength after 3 days is high and reach 86.3% of the original compressive strength after 28 days.Second,its workability is perfect,the anti-separating performance is good ,the distributing of every ingredient is well-proportioned when the fresh concrete is cast into column whose height is four meters.Third, its module of elastic is 4.6×10^4 MPa, not perior to common concrete.Forth, the 360 d free expansivity is 6.9×10^-4.