装配式混凝土叠合板拆模起吊安全性监测数据

装配式混凝土叠合板是建筑行业中非常重要的装配式构件，施工方在施工现场需要在预制底板上浇筑一定厚度的混凝土叠合层，使其与预制底板形成整体共同受力。为了确保构件的起吊施工安全，减免构件实体破坏、开裂漏水和报废造成经济损失，叠合板拆模起吊安全性的数据监测是建筑行业必不可少的工作。该监测数据能够评估装配式混凝土叠合板拆模起吊施工安全性，帮助施工方判断该工程是否满足安全拆模起吊要求，能否按时拆模起吊，对建筑行业的工程质量、施工进度、人员安全等具有无法替代的重要意义。 依据国家标准GB/T 50081-2019《混凝土物理力学性能试验方法标准》进行制作边长为100mm的立方体混凝土试件，在现场同条件养护24h用标准试验方法检测得立方体抗压强度。按照如下公式计算：fcc=F/A，公式中fcc为混凝土立方体试件抗压强度，单位为MPa，计算结果应精确至0.1MPa；F为试件破坏载荷，单位为N；A为试件承压面积，单位为mm2。混凝土强度等级小于C60时，用边长为100mm的立方体非标准试件测得的强度值均应乘以尺寸换算系数0.95。再分别计算出三个试件的抗压强度值，取平均值作为该组试件抗压强度代表值fcuo，与设计强度标准值进行相除，得到最后的达到设计强度百分比。综上所述，达到设计强度百分比的计算公示为p=(/F1/A*0.95+F2/A*0.95+F3/A*0.95)/3/fcuo，结果精确至1%。按安全拆模起吊规范要求，同条件养护混凝土试件抗压强度不应小于设计强度的50%，未满足要求，不得拆模起吊，必须延迟起吊时间。经计算分析，该批构件满足安全拆模起吊要求，可以按时拆模起吊。

Precast concrete composite slabs are critical prefabricated components in the construction industry. On construction sites, contractors need to pour concrete overlay layers of a specified thickness on the precast bottom slabs, so that they form an integrated whole with the precast bottom slabs to jointly bear loads. To ensure the safety of component lifting construction, reduce physical damage, cracking, water leakage and economic losses resulting from component scrapping, data monitoring of the safety of formwork removal and lifting for composite slabs is an indispensable task in the construction industry. This monitoring data can evaluate the safety of formwork removal and lifting construction for precast concrete composite slabs, help contractors determine whether the project meets the safety requirements for formwork removal and lifting, and whether it is possible to remove the formwork and lift on schedule. It has irreplaceable and vital significance for the project quality, construction schedule, personnel safety and other aspects of the construction industry. Cubic concrete specimens with a side length of 100 mm were fabricated in accordance with the national standard GB/T 50081-2019 *Standard for Test Method of Physical and Mechanical Properties of Concrete*, and their cubic compressive strength was tested using standard test methods after being cured on-site under the same conditions for 24 hours. The calculation is performed according to the following formula: $f_{cc} = F/A$, where $f_{cc}$ represents the compressive strength of the concrete cubic specimen, with the unit of MPa, and the calculation result shall be accurate to 0.1 MPa; $F$ is the failure load of the specimen, with the unit of N; $A$ is the bearing area of the specimen, with the unit of mm². When the concrete strength grade is lower than C60, the strength values measured with 100 mm cubic non-standard specimens shall all be multiplied by the size conversion factor of 0.95. Then the compressive strength values of the three specimens are calculated separately, and the average value is taken as the representative compressive strength $f_{cuo}$ of this group of specimens. Divide this value by the standard value of design strength to obtain the final percentage of reaching the design strength. In summary, the calculation formula for the percentage of reaching the design strength is $p = [(F_1/A × 0.95 + F_2/A × 0.95 + F_3/A × 0.95) / 3] / f_{cuo}$, and the result shall be accurate to 1%. According to the specifications for safe formwork removal and lifting, the compressive strength of concrete specimens cured under the same conditions shall not be less than 50% of the design strength. If the requirement is not satisfied, formwork removal and lifting are not permitted, and the lifting time must be delayed. Through calculation and analysis, this batch of components meets the requirements for safe formwork removal and lifting, and can remove the formwork and lift on schedule.