回弹法检测混凝土抗压强度技术规程摘要1.回弹仪使用方法要点:缓慢施压,准确读数,快速复位。2.构件的抽查数量:不得少于同批构件总数的30%且构件数量不得少于10件。3.测区1)每一结构或构件测区数不应少于10个,对某一方向尺寸小于4.5m且另一尺寸小于0.3m的构件,其测区数可适当减少,但不应少于5个;2)相邻测区的间距应控制在2m以内,测区离端部,边缘的距离不宜大于0.5m,且不小于0.2m;3)测区应均匀分布,在重要部位及薄弱部位必须布置测区,并应避开预埋件;4)测区的面积不宜大于0.04m2;5)检测面应清洁、平整。6)对弹击时产生颤动的薄壁、小型构件应进行固定。4•测点:在测区范围内宜均匀分布,相邻两测点的净距不宜小于20mm;测点距外露钢筋、预埋件距离不宜小于30mm。测点不应在气孔或外露石子上,同一测点只应弹击一次。每一测区应记取16个回弹值,估读至1。5.碳化深度值测量1)测量值测量完毕后,应在有代表性的位置上测量碳化深度值,测点不应少于构件测区数的30%,取其平均值为该构件每测区的碳化深度值,当碳化深度值极差大于2.0mm时,应在每一测区测量碳化深度值。2)可采用适当工具在测区表面形成直径约15mm的孔洞,其深度应大于混凝土碳化深度。孔洞中的粉未和碎屑应除净,并不得用水擦洗。同时应采用浓度为1%的酚酞溶液滴在孔洞内壁的边缘处,当已碳化与未碳化界线清楚时,再用深度测量工具测量已碳化与未碳化混凝土交界面到混凝土表面的垂直距离,测量不应少于3次,取其平均值。每次读数精确至0.5mm。混凝土强度推定值计算程序修正值是指“用代数方法与未修正测量结果相加,以补偿其系统误差的值”。当计量器具的示值误差为已知时,则可通过减去(当示值误差为正值时)或加上(当示值误差为负值时)该误差值,使测量值等于被测量的实际值。减去或加上的这个值即为修正值,它与示值误差在数值上相等,但符号相反。测区混凝土强度换算值:由则区的平均回弹值和碳化深度值通过测强曲线计算得到的该检测单元的现龄期混凝土抗压强度值。混凝土强度换算表附录A测区混凝土强度换算表平均回测区混礙土強度换算值人5(MPa)平均碳化深度值cUunn)00.51.01.52.()2.53.03.54.04.55.05.526.020.010.310.120.210.510.310.0——————————20.410.710.510.220.611.010.810.410.1—————————20.811.211.010.610.3—————————21.011.411.210.810.510.021.211.611.411.010.710.2———21.411.811.611.210.910.410.0——21.612.011.811.411.010.610.221.812.312.111.711.310.810.510.122.012.512.211.911.511.010.610.2——————22.212.712.412.111.711.210.810.410.0—————22.413.012.712.412.011.411.010.710.310.0————22.613.212.912.512.111.611.210.810.410.2————22.813.413.112.712.311.811.411.010.610.3————23.013.713.413.012.612.111.611.210.810.510.1———23.213.913.613.212.812.211.811.411.010.710.310.0——23.414.113.813.413.012.412.011.611.210.910.410.2——23.614.414.113.713.212.712.211.811.411.110.710.410.1—23.814.614.313.913.412.812.412.011.511.210.810.510.2—24.014.914.614.213.713.112.712.211.811.511.010.710.410.1续表续表续表续表平均回弹测凶混凝土强度换算苗九"(MPa)值甌平均碳化深度値cUfinm)00.51.01.52.02.53.0S.54.04.55.05.5>6039.239938.537.035.033.332.130.829.829.027.626225.024.039.440338.837.335.3S3.石32J3L030.029227.826.425.224.239.640.739.137.635.633.932.731230229.428..026.625.424439S41239.638.035.934.233.030.529.728.22&名25.624.740,041639.938.3迢234.533.33L730,830,02&427.Q2戏25.040.242.040.338.636.534.833.632.031.130228.627.326.025.240.442.44Q.739.036.9辽133.932.331J30.52&吕27.626.225A40.642.841.139.437.235.434.232.631.730.829.127.826.525.740.843.341.639.S37.735.734.532.932.031.229.428.126.826.041.043.742.040.238.036.034.833.232.331.529.728.427.126.241244142344).638.43&335.133.532.631830.028.727.326.541444.542.740938.7...