混凝土强度等级检测(回弹试验)附砼强度换算值.doc

混凝土强度等级检测(回弹试验)回弹法检测砼强度试用于工程结构普通砼抗压强度的检测。砼强度值的确定分为如下几个步骤：1、 回弹值测量 2、 2、碳化深度值测量 3、 3、回弹值计算 4、 4、砼强度的计算一、 回弹值测量1、 一般规定：结构或物件砼强度检测可采用下列两种方式，其适用范围及结构或构件数量应符合下列规定：（1）、单个检测：适用于单个结构或构件的检测。（2）、批量检测：适用于相同的生产工艺条件下，砼强度等级相同，原材料、配合比、成型工艺、养护条件基本一致且龄期相近的同类结构或构件，按批进行检测的结构构件。抽检数量不得少于同批构件总数的30%且不得少于10件。2、每一结构或构件的测区应符合下列规定：（1）、每一结构或构件测区数量应不少于10个。对某一方向尺寸小于4.5米，且另一方向尺寸小于0.3米的构件其测区数量可适当减少，但不应少于5个。（2）、相邻两测区的间距应控制在2米以内。测区离构件端部或施工缝边缘的距离不宜大于0.5米，且不宜小于0.2米。（3）、测区应选在使回弹仪处于水平方向检测砼浇筑侧面，当不能满足这一要求时，可使回弹仪处于非水平方向检测砼强度浇筑侧面、表面或底面。但回弹值需修正。（4）、测区宜选在构件的两个对称可测面上，也可选在一个可测面上，且应均匀分布。在构件的重要部位及薄弱部位必须布置测区，并应避开预埋件。（5）、测区的面积不宜大于0.04。（6）、检测面应为砼表面，并应清洁平整，不应有疏松层、浮浆、油垢、涂层以及蜂窝、麻面。必要时可用砂轮清除疏松层和杂物，且不应有残留的粉末或碎屑。3、回弹值测定（1）、检测时，回弹仪的轴线应始终垂直于结构或构件的检测面。缓慢施压，准确读数，快速复位。（2）、测点宜在测区范围内均匀分布。相邻两测点的净距不宜小于20mm。测点距外露钢筋、预埋件的距离不宜小于30mm。测点不应在气孔或外露石子上，同一测点只应弹一次，每一测区应取16个回弹值。二、 碳化深度测量值1、 回弹值测量完毕后，应在有代表性的位置上测量碳化深度值。测点不应小于构件测区数的30%，取其平均值为该构件的每测区的碳化深度值，当碳化深度最大值与最小值之差大于2.0mm时，应在每一测区测量碳化深度。2、 碳化深度值测量，可采用适当的工具在测区表面形成直径约15mm孔洞，其深度应大于砼的碳化深度。孔洞中的粉末和碎屑应清除干净，并不得用水擦洗。同时，应采用浓度为1%的酚酞酒精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砼交界面到砼表面的垂直距离。测量应不少于3次，取其平均值。每次读数精确至0.5mm。碳化深度修正系数表 表1实测强度碳化深度d(mm)12345610-200.950.880.820.770.720.6820-300.940.860.800.740.700.6230-400.930.840.780.730.660.6040-500.920.820.760.720.650.6050-600.910.800.740.710.640.60三、 回弹值计算1、计算测区平均回弹值，应该从该测区的16个回弹值中剔除3个最大值和3个最小值，求余下的10个回弹值的平均值，如果是水平方向回弹浇筑砼的侧面，该值即为该测区平均回弹值Rm。如果不足，此值还需修正。2、 非水平方向检测砼浇筑侧面时， 应按下列修正: Rm=Rm+Ra式中 Rm：非水平状态检测时测区的平均回弹值，精确到0.1Ra：非水平状态检测时回弹值修正值，可按本附表1采用。Rm：测区平均回弹值（修正后）非水平状态检测时回弹值修正值 表1测试角度检测角度+90+60+45+30-30-45-60-9020-6.0-5.0-4.0-3.0+2.5+3.0+3.5+4.030-5.0-4.0-3.5-2.5+2.5+3.0+3.5+4.040-4.0-3.5-3.0-2.0+1.5+2.0+2.5+3.050-3.5-3.0-2.5-1.5+1.0+1.5+2.0+2.53、 水平方向检测砼浇筑顶面或底面时， 应按下列修正：Rm=+ Rm=+式中：Rm:测区修正后平均回弹值 ：水平方向检测砼浇筑表面时，测区平均回弹值。：砼浇筑表面回弹值的修正值，见附表2。：水平方向检测砼浇注底面时，测区平均回弹值。：砼浇筑底面回弹值的修正值。见附表24 当检测时回弹仪为非水平方向且测试面为非砼的浇筑侧面时。应先按附表1对回弹值进行角度修正。再按附表2对修正后的值进行浇筑面修正。即：先修正角度，再修正浇筑面。 不同浇筑面的回弹值修 表2或表面修正值()底面修正值()或表面修正值()底面修正值()20+2.5-3.040+0.5-1.025+2.0-2.5450-0.530+1.5-2.0500035+1.0-1.5四、砼强度的计算（平均强度）1、经过以上砼回弹数值测量。回弹数值修正。碳化深度测量后，可利用平均回弹修正数值（Rm）及平均碳化深度（dm）,查附表3,可求得各个测区砼强度换算值。2根据各个测区的砼强度换算值可计算测区砼强度平均值。当测区数为10个及以上时，应计算强度标准差，平均值及标准差应按下式计算： ，式中：结构或构件测区砼强度换算值的平均值。n：对于单个检测的构件，取一个构件的测区数；对批量检测的构件，取被抽检构件的测区之和。：测区砼强度换算值。：结构或构件测区砼强度换算值的标准差。3、 结构或构件砼强度推定值（）的计算：结构或构件的砼强度推定值即是砼强度值，是指相应于强度换算值总体分布中保证率不低于95%的结构或构件中的砼抗压强度值。即：查表或据测强度曲线得出的强度换算值中有95%的值小于砼强度指定值。（1）、当该结构或构件测区数少于10个时，强度推定值取强度换算值中最小的1个。即=min()(2)、当该结构或构件的测区强度值中出现小于10.0Mpa这个数值时，砼强度值指定值则取小于10.0Mpa。即<10.0Mpa这个数值一般不出现。在测强度曲线和换算值表中也查不到，所以当出现砼强度换算值<10.0Mpa时。砼强度推定值不用计算，直接取<10.0Mpa。（3）、当该结构或构件测区数不少于10个或按批量检测时，砼强度推定值：砼强度换算值 表3平均回弹值平均碳化深度值dm(mm)Rm00.511.522.533.544.555.562010.310.120.210.510.31020.410.710.510.220.61110.810.410.120.811.21110.610.32111.411.210.810.51021.211.611.41110.710.221.411.811.611.210.910.41021.61211.811.41110.610.221.812.312.111.711.310.810.510.12212.512.211.911.51110.610.222.212.712.412.111.711.210.810.41022.41312.712.41211.41110.710.31022.613.212.912.512.111.611.210.810.410.222.813.413.112.712.311.811.41110.610.32313.713.41312.612.111.611.210.810.510.123.213.913.613.212.812.211.811.41110.710.31023.414.113.813.41312.41211.611.210.910.410.223.614.414.113.713.212.712.211.811.411.110.710.410.123.814.614.313.913.412.812.41211.511.210.810.510.22414.914.614.213.713.112.712.211.811.51110.710.410.124.215.114.814.313.913.312.812.411.911.611.210.910.610.324.415.415.114.614.213.613.112.612.211.911.411.110.810.424.615.615.314.814.413.713.312.812.31211.511.210.910.624.815.915.615.114.61413.51312.612.211.811.411.110.72516.215.915.414.914.313.813.312.812.51211.711.310.925.216.416.115.615.114.413.913.41312.612.111.811.51125.416.716.415.915.414.714.213.713.212.912.41211.711.225.616.916.616.115.714.914.413.913.41312.512.211.811.325.817.216.916.315.815.114.614.113.613.212.712.41211.52617.517.216.616.115.414.914.413.813.51312.612.211.626.217.817.416.916.415.715.114.61413.713.212.812.411.826.41817.617.116.615.815.314.814.213.913.31312.61226.618.317.917.416.816.115.61514.414.113.513.212.812.1Rm00.511.522.533.544.555.5626.818.618.217.717.116.415.815.314.614.313.813.412.912.32718.918.51817.416.616.115.514.814.61413.613.112.427.219.118.718.117.616.816.215.71514.714.113.813.312.627.419.41918.417.81716.415.915.214.914.31413.412.727.619.719.318.71817.216.616.115.415.114.514.113.612.927.82019.61918.217.416.816.315.615.314.714.213.7132820.319.719.218.417.61716.515.815.414.814.413.913.228.220.62019.518.617.817.216.71615.61514.61413.328.420.920.319.718.81817.416.916.215.815.214.814.213.528.621.220.62019.118.217.617.116.41615.41514.313.628.821.520.920.219.418.517.817.316.616.215.615.214.513.82921.821.120.519.618.718.117.516.816.415.815.414.613.929.222.121.420.819.91918.317.71716.61615.614.814.129.422.421.721.120.219.318.617.917.216.816.215.81514.229.622.72221.320.419.518.818.217.51716.41615.114.429.82322.321.620.719.819.118.417.717.216.616.215.314.53023.322.621.9212019.318.617.917.416.816.415.414.730.223.622.922.221.220.319.618.918.217.61716.615.614.930.423.923.222.521.520.619.819.118.417.817.216.815.815.130.624.323.622.821.920.920.219.418.71817.5171615.230.824.623.923.122.121.220.419.718.918.217.717.216.215.43124.924.223.422.421.420.719.919.218.417.917.416.415.531.225.224.423.722.721.720.920.219.418.618.117.616.615.731.425.624.824.1232221.220.519.718.918.417.816.915.831.625.925.124.323.322.321.520.719.919.218.61817.11631.826.225.424.623.622.521.72120.219.418.918.217.316.23226.525.724.923.922.82221.220.419.619.118.417.516.432.226.926.125.324.223.122.321.520.719.919.418.617.716.632.427.226.425.624.523.422.621.820.920.119.618.817.916.832.627.626.825.924.823.722.922.121.320.419.91918.11732.827.927.126.225.12423.222.321.520.620.119.218.317.23328.227.426.525.424.323.422.621.720.920.319.418.517.433.228.627.726.825.724.623.722.92221.220.519.618.717.633.428.92827.12624.92423.122.321.420.719.818.917.833.629.328.427.426.425.224.223.322.621.720.92019.11833.829.628.727.726.625.424.423.522.821.921.120.219.318.2343029.12826.825.624.623.72322.121.320.419.518.334.230.329.428.32725.824.823.923.222.321.520.619.718.4Rm00.511.522.533.544.555.5634.430.729.828.627.2262524.123.422.521.720.819.818.634.631.130.228.927.426.225.224.323.622.721.9212018.834.831.430.529.227.626.425.424.523.822.922.121.220.2193531.830.829.62826.725.824.82423.222.321.420.419.235.232.131.129.928.227262524.223.422.521.620.619.435.432.531.530.228.627.326.325.424.423.722.821.820.819.635.632.931.930.62927.626.625.724.72423222119.835.833.332.33129.328272602524.323.322.221.23633.632.631.229.628.227.226.225.224.523.522.421.420.236.2343331.629.928.627.526.525.524.823.822.621.620.436.434.433.43230.328.927.926.825.825.124.122.821.820.636.634.833.832.430.629.228.227.126.125.424.4232220.936.835.234.132.73129.628.527.526.425.724.623.222.221.13735.534.43331.229.828.827.726.625.924.823.422.421.337.235.934.833.431.630.229.12826.926.225.123.722.621.537.436.335.233.831.930.529.428.327.226.525.42422.921.837.636.735.634.132.330.829.728.627.526.825.724.223.12237.837.13634.532.631.23028.927.827.12624.523.422.33837.536.434.93331.530.329.228.127.426.224.823.622.538.237.936.835.233.431.830.629.528.427.726.52523.922.738.438.337.235.633.732.130.929.828.72826.825.324.12338.638.737.53634.132.431.230.12928.32725.524.423.238.839.137.936.434.432.731.530.429.328.527.225.824.623.53939.538.236.734.73331.830.629.628.827.42624.823.739.239.938.5373533.332.130.829.82927.626.2252439.440.338.837.335.333.632.4313029.227.826.425.224.239.640.739.137.635.633.932.731.230.229.42826.625.424.439.841.239.63835.934.23331.430.529.728.226.825.624.74041.639.938.336.234.533.331.730.83028.42725.82540.24240.338.636.534.833.63231.130.228.627.32625.240.442.440.73936.935.133.932.331.430.528.827.626.225.440.642.841.139.437.235.434.232.631.730.829.127.826.525.740.843.341.639.837.735.734.532.93231.229.428.126.8264143.74240.2383634.833.232.331.529.728.427.126.241.244.142.340.638.436.335.133.532.631.83028.727.326.541.444.542.740.938.736.635.433.832.93230.328.927.626.741.64543.241.439.236.935.734.233.332.430.629.227.92741.845.443.641.839.537.23634.533.632.730.929.528.127.2Rm00.511.522.533.544.555.564245.944.142.239.937.636.334.9343331.229.828.527.542.246.344.442.640.33836.635.234.333.331.530.128.727.842.446.744.84340.638.336.935.534.633.631.830.4292842.647.245.343.441.138.737.335.934.93432.130.729.328.342.847.645.743.841.43937.636.235.234.332.430.929.528.64348.146.244.241.839.43836.635.634.632.731.329.828.943.248.546.644.642.239.838.336.935.934.93331.530.129.143.4494745.142.640.238.737.236.335.333.331.830.429.443.649.447.445.44340.53937.536.635.633.632.130.629.643.849.947.945.943.440.939.437.936.935.933.932.430.929.94450.448.446.443.841.339.838.337.336.334.332.831.230.244.250.848.846.744.241.740.138.637.636.634.53331.530.544.451.349.247.244.642.140.5393836.934.933.331.830.844.651.749.647.64542.440.839.338.337.235.233.632.13144.852.250.14845.442.841.239.738.637.635.533.932.431.34552.750.648.545.843.241.640.13937.935.834.332.731.645.253.251.148.946.343.64240.439.438.336.234.63331.945.453.651.549.446.64442.340.739.738.636.434.833.232.245.654.151.949.847.144.442.741.1403936.835.233.532.545.854.652.450.247.544.843.141.540.439.337.135.533.932.8465552.850.647.945.243.541.940.839.737.535.834.233.146.255.553.351.148.345.543.842.241.14037.736.134.433.346.45653.851.548.745.944.242.641.440.338.136.434.733.646.656.554.25249.246.344.642.941.840.738.436.73533.946.85754.752.449.646.74543.342.24138.83735.334.24757.555.252.95047.245.243.742.641.439.137.435.634.547.25855.753.450.547.645.844.142.941.839.437.73634.847.458.556.253.850.94846.244.543.342.139.83836.335.147.65956.654.351.348.446.644.843.742.540.138.436.635.447.859.557.154.751.848.84745.24442.840.538.736.935.7486057.655.252.249.247.445.644.443.240.83937.23648.25855.752.649.647.84644.843.641.139.337.536.348.458.656.153.15048.246.445.143.941.539.637.836.648.65956.653.550.448.646.745.544.341.84038.136.948.859.557.15450.94947.145.944.642.240.338.437.2496057.554.451.349.447.546.24542.540.638.837.549.25854.851.749.847.946.645.442.84139.137.849.458.555.352.150.248.347.145.843.241.339.438.2Rm00.511.522.533.544.555.5649.658.955.752.550.648.747.446.243.641.739.738.549.859.456.2535149.147.846.543.94240.138.85059.956.753.451.449.548.246.944.342.340.439.150.257.153.851.949.948.547.244.642.640.739.450.457.654.352.350.34947.745434139.750.65854.752.750.749.44845.443.441.44050.858.555.153.151.149.848.445.743.741.740.3515955.653.551.550.148.846.144.14240.751.259.4565451.950.549.246.444.442.34151.459.956.454.452.350.949.646.844.742.741.351.656.954.852.751.35047.245.14341.651.857.355.253.151.750.347.545.443.341.85257.855.753.652.150.747.945.843.742.352.258.256.15452.551.148.346.24442.652.458.756.554.45351.548.746.544.44352.659.15754.853.451.94946.944.743.352.859.657.455.253.852.349.447.345.143.6536057.855.654.252.749.847.645.443.953.258.356.154.653.150.24845.844.353.458.756.55553.550.548.346.144.653.659.256.955.453.950.948.746.444.953.859.657.355.854.351.34946.845.35457.856.354.751.749.447.145.654.258.256.755.152.149.847.54654.458.657.155.652.550.247.946.354.659.157.55652.950.548.246.654.859.557.956.453.250.948.5475559.958.456.853.651.348.947.355.258.857.25451.649.347.755.459.257.654.45249.64855.659.75854.852.45048.455.858.555.252.850.348.75658.955.653.250.749.156.259.35653.551.149.456.459.756.453.951.449.856.656.854.351.850.156.857.254.752.250.55757.655.152.550.8Rm00.511.522.533.544.555.5657.25855.552.951.257.458.455.953.351.657.658.956.353.751.957.859.356.75452.35859.75754.452.758.257.454.85358.457.855.253.458.658.255.653.858.858.655.954.1595956.354.559.259.456.754.959.459.857.155.259.657.555.659.857.9566058.356.4