某工程砌筑砖墙,设计规定用黏土砖Mц10。混合砂浆M5,施工时作砂浆试块一组,试块尺寸为70.7×70.7×70.7(mm),经28d标养,做抗压试验,其破坏荷载分别为:37.5,32.5,35.0,37.5,30.0,30.0,(KN)计算该组试块的强度代表值?该强度达设计标号的百分比?
正确答案:试块承压面积 S=70.7×70.7=4998.49(mm2)
试块强度:
R1=37500N/4998.49=7.50 (мpa)
R2=32500N/4998.49=6.50 (мpa)
R3=35000N/4998.49=7.00 (мpa)
R4=37500N/4998.49=7.50 (мpa)
R5=30000N/4998.49=6.00 (мpa)
R6=30000N/4998.49=6.00 (мpa)
该组试块请度代值R=(7.50+6.50+7.00+7.50+6.00+6.00)/6 =6.80(Мpa)
试块强度占设计强度%:6.80/5.00=1.36=136%
试块强度:
R1=37500N/4998.49=7.50 (мpa)
R2=32500N/4998.49=6.50 (мpa)
R3=35000N/4998.49=7.00 (мpa)
R4=37500N/4998.49=7.50 (мpa)
R5=30000N/4998.49=6.00 (мpa)
R6=30000N/4998.49=6.00 (мpa)
该组试块请度代值R=(7.50+6.50+7.00+7.50+6.00+6.00)/6 =6.80(Мpa)
试块强度占设计强度%:6.80/5.00=1.36=136%
答案解析:有
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