利用正交试验法研制结构用陶粒轻骨料混凝土

Development of ceramsite lightweight aggregate concrete for structures by orthogonal test method

为满足建筑结构对轻质构件的需求,进行正交配合比试验设计,研制LC35结构用陶粒轻骨料混凝土(LACC)。依据标准进行配合比计算,通过试制试验、多变量数据分析,得出影响LACC强度的影响因子水平,包括净水胶比、粉煤灰掺量、陶粒掺量和砂率。采用极差和方差分析,确定影响LACC 28d抗压强度因素的主次顺序为陶粒掺量>净水胶比>砂率>粉煤灰掺量,陶粒掺量480kg、净水胶比0.36、粉煤灰掺量20%、砂率42%为最优方案,且各因素不对28d抗压强度产生差异关系。最佳配合比净水胶比0.36、水泥360kg、粉煤灰90kg、陶粒480kg、砂775kg、减水剂4.5kg,LACC 28d抗压强度达到45MPa以上,满足轻骨料混凝土结构用强度要求。

LC35 ceramsite lightweight aggregate concrete(LACC) for structure is developed to meet the requirements of lightweight components in building structures by orthogonal mix design. According to the standard, the mix ratio is calculated. Through the trial test and multivariate data analysis, the level of influencing factors affecting the strength of LACC for structure is obtained, including water-binder ratio, fly ash content, ceramsite content and sand ratio. Based on range and variance analysis, the primary and secondary order of factors affecting the 28-day compressive strength of LACC is determined as follows: ceramsite content > water-binder ratio > sand ratio > fly ash content. The optimal scheme is ceramsite content 480kg, water-binder ratio 0.36, fly ash content 20%, sand ratio 42%, and all four factors have no different relationship with the 28-day compressive strength. The best mix ratio is water-binder ratio 0.36, cement 360kg,fly ash 90kg, ceramsite 480kg, sand 775kg, water reducer 4.5kg. The 28-day compressive strength of LACC reaches more than 45MPa, which meets the strength requirements of lightweight aggregate concrete structure.