【填空题】253 / 541已知fcu,k=30 MPaf_{cu,k}=30\,\mathrm{MPa}fcu,k=30MPa，σ=5.0 MPa\sigma=5.0\,\mathrm{MPa}σ=5.0MPa，按fcu,0=fcu,k+1.645σf_{cu,0}=f_{cu,k}+1.645\sigmafcu,0=fcu,k+1.645σ计算配制强度约为____MPa\mathrm{MPa}MPa。参考答案暂无参考解析30+1.645×5≈38.2 MPa30+1.645\times 5\approx 38.2\,\mathrm{MPa}30+1.645×5≈38.2MPa。
