【摘要】 针对壁薄面大、以振动成型为主、易收缩开裂的预制混凝土外墙板,采用活性掺合料、膨胀剂和微细钢纤维等多元混掺技术,进行外墙板用自密实混凝土的配合比优化、配制和物理力学性能试验,并用于多孔外墙板的浇注成型。试验结果表明,在本研究条件下,单掺膨胀剂及复掺微细钢纤维时,自密实混凝土的扩展度为620⁶40 mm,T₅₀₀在10 s左右,工作性能和表观质量良好;混凝土7 d和28 d抗压强度的变化幅度分别在5%和10%以内,60 d干燥收缩率可降低65%⁷5%,体积稳定性良好。更多还原

【Abstract】 Aiming at the prefabricated concrete exterior wall panels with large wall thickness,vibration shaping and easy shrinkage and cracking,optimization of the compounding ratio,preparation,and physical and mechanical properties test of self-compacting concrete for exterior wall board is carried out by using multiple admixture technologies such as reactive admixture,expansive agent and micro-steel fiber,and for the perforated exterior wall molding. The test results show that the expansion of self-compacting concrete is about 620 ~640 mm,the T500 is about 10 s,and the working performance is good under the conditions of this study. The variation range of the compressive strength of concrete at 7 d and 28 d is less than 5% and less than 10%,respectively,the drying shrinkage after 60 days can be reduced by about 65%~75%,and the volume stability is good.更多还原