Surveying technique to the structural opening found in the RC beam

Professional Building Surveyors are always called on board to do structural survey. There is one situation where the RC beam is cored with the opening and this caused a lot of anxious to the occupier about its structural safety. Usually , the surveying to this kind of damaged structural elements are tricky and professional. It needs to review the original structural frame ; RC beam rebar details , slab thickness and the exact position of opening being formed on the beam section

Details of infrastructure – Construction worker hands securing steel bars with wire rod for reinforcement of concrete

Since the reinforced concrete beam is composed of the rebars configured in designated position to achieve different structural purpose, thus , the inspection to the opening . To ensure a complete and proper visual inspection to the rebar is in place , we adopt the endoscope to inspect also the inside view of the opening . It is to technically identify whether any rebar has been damaged. Also , it helps to ensure the opening was not backfilled with undesirable materials.


Once the visual inspection is done and recorded , we need to cross check with the original design and identify the fall-short and assess the physical damage. Sometimes, we need the input from Structural Design to advise the structural loading capacity effect from the physical damage

Since the portal frame can be either fixed joint or pin joint in nature , thus the beam may exhibit different bending moment . The opening formed on the beam may diminish much the bending moment capacity of beam if the opening were wrongly poised and erred sized