| Welded Steel Fabric is the steel net slice,which refers to using the cold-rolled ribbed bars or fine diameter hot-rolled ribbed reinforcement which can comply with provisions of applicable national standard,using special resistance welder to made in the factory,by the same or different diameter longitudinal reinforcement and the transverse respectively by a certain distance between steel vertical arrangement,all the intersection are made of the resistance spot welding together.Welded steel fabric is mainly used for the components of reinforced concrete board,bridge,the road surface,wall plate and so on,but there are also engineering applications in the water pipe,highway or river,storage;protection liquid pools docks in recent years.Welded Steel Fabric has the advantages of good quality in reinforcing steel work,high sproductivity,economize steel,it can supply according to specifications and size,it also in line with the construction engineering factory production direction,application is widened.In order to further standardize reinforced concrete structure and component welding net of design and construction,our country is in revised in the national industry standard of "Technical specification for concrete structures reinforced with welded steel fabric".In order to match the revision of the national industry standard,the experiment is studied by the pull-out tests through out 32 group(96 specimens)different forms of welded steel fabric anchoring the of the specimens,analyzes the strength influence of welds vertical stress horizontal reinforcing steel bar and reinforced the bond-slip behavior anchoring,and put forward the corresponding bond anchorage strength calculation formula and anchor length value suggestions.This paper includes as following works:1.Inspection of the Welding nets of cold-rolled ribbed reinforced mechanical properties and the weld depth.The inspection of Beijing cold-rolled ribbed reinforcement fabric of different diameter of the reinforced sample selection mechanical performance test show that the tensile strength of steel welding nets with cold-rolled ribbed bars can reached more than 500 MPa,uniform elongation ?gt can reach more than 6%,in line with welding nets of reinforced of performance requirements;Although weld depth of the Welded Steel Fabric exists certain dispersion,but in general more or less the same,the average range of weld depth is 1.12mm to 1.64mm,meet the requirements.2.Welded steel fabric and concrete binding anchorage performance tests.Through three kinds of different anchor forms,different bonding state of cold rolled ribbed bar specimens of welded steel fabric anchoring the pull-out tests and analysis,The results show that when the anchorage zone without horizontal reinforcing steel bar,the longitudinal reinforcement of anchorage strength and design anchor length all can follow common cold rolled ribbed reinforcement provisions of value;When the anchorage zone have horizontal reinforcing steel bar,longitudinal reinforcement anchoring strength and stiffness of the anchorage are improved significantly and design anchor length can be reduced;we advice when the anchorage zone have one horizontal reinforcing steel bar,longitudinal reinforcement anchor length can be multiplied by reduction coefficient of 0.8,When the anchorage zone have two horizontal reinforcing steel bar,longitudinal reinforcement anchor length can be multiplied by reduction coefficient of 0.6.The research result of the thesis offered the important reference basis for national standard revision of”Technical specification for concrete structures reinforced with welded steel fabric". |
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