Research On Rapid Of Indoor Floor Crack Caused By Uneven Settlement

Now,the number and severity of cracks in the concrete floor are increasing.Floor crack disease not only detrimental to the appearance,giving no sense of security,and some cracks reduce the overall stiffness and durability of the structure,reducing its mechanical properties and resistance to external ion penetration,and some caused the housing leakage,The use of the function,in particular,need to pay attention to the cracks are sometimes the precursor of damage,crack width,length and quantity to a certain extent,will lead to structural damage.In addition,the floor crack disease on the performance of fast repair materials have a higher demand.The crack repair structure and the quick repair material are the important research directions of the rapid repair technology of concrete floor.This paper mainly studies the cracks of indoor floor caused by uneven settlement from the aspects of repairing materials and repairing structure.In the aspect of repairing materials,the magnesium phosphate cement-based high-strength fast and fast concrete is used as the quick repair material to study the performance of the cracks in the floor.The repairing structure is studied by theoretical analysis and experimental study.And the bond layer on the bonding surface of the shear stress and bond strength,to explore ways to improve the adhesion of new and old concrete interface.And summarizes the rapid repair construction of indoor floor cracks caused by uneven settlement.The final conclusions are as follows:(1)indoor floor crack fast repair materials using magnesium oxide,ammonium dihydrogen phosphate,fly ash and other raw materials prepared by the magnesium phosphate cement to high strength fast hard concrete.The results show that the coagulation time is fast,the early strength is high,the flowability and wear resistance,durability and so on are good.The optimum initial dosage of 5%borax retarder was obtained by comparison test under the condition of high temperature and extreme weather conditions.(2)For the shear stress failure of the bonding surface of the crack structure,the shrinkage shear stress is mainly studied.The theoretical analysis of shrinkage shear stress shows that most of the shrinkage shear stress comes from the self-shrinkage of the new concrete.The shrinkage rate of 1d was 0.0008%,the shrinkage rate of 3d was 0.0023%,the shrinkage rate of 7 days was 0.0065%,and it became basically stable after 90 days.The shrinkage performance of magnesium phosphate cement is better than that of other quick repair materials,and the method of reducing the self-shrinkage of magnesium phosphate cement by reducing the water-cement ratio and using the superplasticizer is given.And the shrinkage cracking test of magnesium phosphate cement was carried out,and it was found that it had good crack resistance.(3)to study the bonding strength of the bonding surface of the floor crack repair structure,analysis of bonding mechanism,influencing factors and improvement measures.For magnesium phosphate cement and ordinary portland cement shear bond test,magnesium phosphate cement has a thin layer to meet the requirements of the bonding force.(4)Based on the design of the quick fixation of the cracks in the indoor floor caused by the uneven settlement,and the experience of repairing the cracks in the floor cracks,a set of quick repair materials based on magnesium phosphate cement-based high-strength fast-hard concrete,Construction Technology and Quality Control Measures of Floor Fissure Repair.