| 1 .IntruductionThe non-disrepair is the technic that using the sound, light, heat, electricity, magnetism and radial, mensurating some data about concrete performance and presume the concrete compressive strength, the lacuna of concrete and so on, without destroying the concrete structure and influencing its workability. The partial disrepair methods, as drilling method, pulling-out method and so on, also belong to the non-disrepair inspection methods in broad sense because that using this type methods to inspect buildings can't bring the safety problem.The technic play an important role in the aspects of ensuring the quality of the new buildings and evaluating the security of the old buildings and are used widely in the world.With the developments of the structure types and the commercial concrete, the components of concrete and the construction technics have been taking great changes. Comparing with the existing correlation, the relationship between the compressive strength of concrete and the data about concrete performance is also changed. The existing inspecting curves of the non-disrepair only apply to the common concrete of which the grade is below C50 and obviously can't be applicable for commercial concrete, especially for high strength concrete. The purpose of this paper is: 1 building the local inspecting curve of the 4 non-disrepair methods which are available to the commercial concrete with the grade from C20-C80; 2 comparing and evaluating the 4 non-disrepair methods and giving some advise.2.Experiment in briefOn the behalf of the commercial concrete from Zhengzhou city, the experiment has been done. The actual strength of concrete is from 24.8MPa to 88.2MPa.In the test, the 12 pure block were used which are 1500mm long, 600mm wide and 1200mm high and cured in nature; the 365 cube samples are 100mm high and cured in nature and standard station. Considering the feasibility and rationality of the experiments, the order of the test is in following:1 On block: rebound test â†'ultrasonic test â†' pulling-out test â†' drilling test2On cube: rebound test â†'ultrasonic test â†' compressive stress test3.Drilling MethodThe drilling method is the partial disrepair inspecting method that using the special equipment, directly drilling cylinders from the structure and basing on the cylinder compressive strength to deduce the structure strength. The method provides us direct and credible inspecting results and has been used in many countries. In the modern concrete structure, the space between the steels is more and more small. According to inspection specification (CECS03:88), the steel maybe exit in cylinder samples when using the drilling method to inspect structure and the effect of the steel to cylinder compressive strength is very complex. So it is necessary to study on using the small cylinder to inspect concrete strength.In the test, the cylinder with 100mm diameter and HID (the ratio of the height divide diameter)=l is the standard sample and its compressive strength can be regard as the factual strength of the structure. The cylinder with 73mm diameter and ///D=1.0~2.0 is the non-standard sample and its compressive strength is the inspecting strength. In the experiment the cylinder of different diameter was be drilled in pairs.By data processing and error analysis, the formula used the compressive strength of the cylinder with 73mm diameter to calculate the structure concrete strength is gotten and can be applied to the high strength concrete.4.Pulling-out MethodThe pulling-out method is also the partial disrepair inspecting method that embedding anchor in sclerous concrete and measuring the pulling-out resistance, which is also called CAPO test. Now, it have two problem in using the method to deduce the structure strength: Ithe rang of the concrete strength has been changed; 2the correlation between the pulling-out resistance and compressive strength of concrete is also changed.In the test, the pulling-out apparatus with 3 points support was used. First, the pul... |
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