In China, building safety assessment and inspection is an emerging industry, primarily focused on measuring, detecting, identifying, and judging the integrity, damage conditions, and safe usability of buildings. Below, our editor highlights the common building safety inspection methods in recent years. Field detection is a low-probability, high-risk task, closely related to identification work. Field testers know more about what to test than how to test.
1. Home Safety Assessment: Home safety assessments typically require inspectors to formulate corresponding inspection plans based on the actual on-site conditions. Standard inspection items include material strength testing, reinforcement configuration inspection, building deformation detection, and crack detection, among others. Different structural forms have varying focal points for structural inspection methods, such as for reinforced concrete structures, emphasis should be placed on concrete grade, reinforcement configuration, crack distribution, and concrete durability; for masonry structures, the focus should be on masonry strength; for steel structures, the emphasis should be on overall and local deformation, non-destructive testing of welds, cross-sectional dimensions, and structural examination.
2. These areas typically consist of buildings that have been renovated, remodeled, and reinforced. Detailed investigations often have limitations, so the focus of the type tests should be on reviewing the blueprints. Considerations include whether the overall functional changes of the building match the drawings, if the cross-sectional dimensions are consistent with the plans, and whether there are any issues that could affect the normal use of the personnel conducting the assessment.
3. Structural inspections typically involve randomly selecting components and primarily focus on non-destructive testing, with an emphasis on analyzing whether the building's structural system and usage meet the requirements. The safety assessment and testing of reconstructed structures are focused on identifying and checking the strength levels of materials, providing a genuine reference for subsequent inspections. Concrete compressive strength and masonry mortar strength are tested according to the sampling scheme of the "Technical Standard for Structural Test of Buildings" (GB/T 50344-2004), and assumed intervals are provided. The provisions for quality inspection of concrete structures in the upcoming "Technical Standard for On-site Concrete Structure Inspection" can also provide assumed values. The compressive strength of masonry mortar can also be evaluated according to the "Technical Standard for On-site Inspection of Masonry Engineering" (GB/T 50315-2000) for structural grades.
Currently, the compressive strength of masonry mortar typically ranges between 2.5 MPa, 5 MPa, 7.5 MPa, 10 MPa, 15 MPa, and 20 MPa. However, the grade of masonry mortar in older buildings also includes 0.4 MPa and 1 MPa. Therefore, the selection of the instrument should be targeted based on the testing method. Separate identification and testing should be conducted for the foundation and upper load-bearing sections. When choosing to perform non-destructive or damage testing on the upper load-bearing sections, the suitability of the on-site testing conditions should be thoroughly considered.
For example, in concrete testing methods, the commonly used concrete strength testing methods in our country have an error range as shown in Table 1. From the table, it can be seen that the core strength testing method for concrete is close to the actual strength grade. However, due to the large scale of damage detection, influence range, and construction, the ultrasonic rebound synthetic method is generally selected. In digital testing, the core method is often used in disputes or judicial appraisals.