Historic Building Inspection

According to the different purposes of testing and evaluation, the testing and evaluation of historical buildings is divided into two categories: comprehensive testing and evaluation of houses and testing and evaluation of the trend of housing integrity.


I. Review of architectural drawings, mapping and use of load survey requirements


Review and mapping of architectural drawings should include architectural plan, elevation, section, as well as features, historical significance, the protection of parts of the detail samples.


The review and mapping of architectural drawings shall include structural plan layout, component size form, and representative component cross-section size, reinforcement structure, node connection structure details.


When the original design structural drawings are more complete, the testing of component section and reinforcement using sampling method for review and testing; the original design structural drawings are incomplete or the section or reinforcement of the extracted components do not match with the original drawings, the sampling volume of similar components should be increased to find out the law of the actual cross-section or reinforcement.


Historic Building Inspection

Second, the mechanical properties of materials testing requirements


Historical building materials mechanical properties testing, non-destructive testing should be used in combination with damage detection methods. The use of non-destructive methods of detection, should first investigate the actual material type, determine the applicability of non-destructive methods used; unless the site conditions do not allow, non-destructive test results should be corrected by the results of the calibration of the broken test results. Concrete strength testing, non-destructive methods should give priority to ultrasonic rebound synthesis method, higher protection requirements, poor field testing conditions can also be used rebound method, but both methods should be corrected by core drilling calibration.


The strength of masonry materials can be detected by indirect method, but the direct method should be used for correction and calibration. Indirect method of masonry materials, clay brick strength can be detected by rebound method, mortar strength can be detected by penetration and rebound method. The direct method of masonry material testing, in situ axial compression method can be used to detect the compressive strength of masonry, or the use of in situ single-brick double-shear method, in situ double-brick double-shear detection of masonry shear strength. Mechanical properties of steel testing, in order to ensure structural safety, should be preferred in the appropriate part of the intercepted specimens directly test direct method; surface hardness method or chemical analysis method for testing is recommended to use the direct method of correction and calibration.


Wood structure testing, should be investigated and confirmed by the wood species, the aging damage to the wood inspection; when there is a significant increase in the load after remodeling, should be cut wood specimens for mechanical properties test, the number of samples should not be less than 3.


Third, housing deformation detection requirements:


The deformation detection of historical buildings includes two items of relative settlement and vertical tilt detection.


Relative settlement can be inferred by measuring the relative height difference of the façade le footing, window sill, floor floor, floor plate bottom, etc.. Before measuring the relative height difference, the site investigation should first determine whether the original design of these parts is at the same elevation and whether the elevation has been changed at a later stage.


The vertical tilt rate can be obtained by measuring the relative tilt of the vertical prism of the facade. The results of tilt measurement should be verified with the relative settlement measurement and analyzed with the distribution pattern of settlement cracks.


Historic Building Inspection

(d) Requirements for the detection of housing damage:


Damage detection of historical buildings include cracks, leakage, facade damage, featured decorative parts damage, concrete carbonization, steel corrosion, brick wall weathering, wood insect, wood decay, wood structure nodes loose failure.


Concrete carbonation depth is appropriate to use the core drilling method for testing, should be given to the measured values and statistical analysis, measured carbonation depth greater than 50mm can not be detected when the specific value. Carbonation depth measurement point as far as possible arranged in the middle of the section, in the corner measurement should be indicated.


Building structure damage distribution should be expressed in plan, elevation or section, typical damage types should be supplemented by photos, video and other representations. Typical parts of the steel rust layer thickness, the thickness of the weathering layer of the brick wall, due to insects and decay caused by the wood structure section weakening degree should be given clear measured values.


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