钢骨轻骨料混凝土受弯构件裂缝宽度试验研究

通过对8根钢骨轻骨料混凝土梁和2根钢骨普通混凝土梁的试验,研究了钢骨轻骨料混凝土受弯构件在单调荷载作用下的裂缝开展与分布情况。试验表明,在正常使用极限状态下,钢骨轻骨料混凝土受弯构件的最大裂缝宽度符合使用要求。与钢骨普通混凝土受弯构件相比,其裂缝宽度稍大,但裂缝宽度变异系数较小。受拉纵筋应力是影响裂缝宽度的最重要因素,二者近似呈线性关系。由于型钢对混凝土具有约束作用,在保护层厚度与有效配筋率两个变量中应考虑型钢的影响。在试验资料和理论分析的基础上,给出了钢骨轻骨料混凝土受弯构件最大裂缝宽度的计算公式。公式的计算结果与实测数据符合较好。

Experimental Study on Crack Width of Steel-reinforced Light-weight Concrete Beams

Based on the experiment of eight steel-reinforced light-weight concrete beams and two steel-reinforced concrete beams,the opening and distribution of cracks are studied and a comparison with two different aggregates has been made to find out wider cracks for light-concrete beams with smaller variations.It is indicated that the stress of tensile bars is the most vital factor affecting the crack width and a linear relationship also develops between the two.While taking into consideration of the effect of steel shape,a formula for the maximum crack width under short-term load of SRLC beams is also proposed with satisfactory agreement obtained between formula results and experimental data.