Research And Development Of Theoretical And Experimental Program About Resistant Weathering Materials In Stone Arch Bridge

It is widely used of stone arch bridges in the mountains of southwest China particularly.Because of the material characteristics and the existed environment of the stone arch bridges, there are many weathering problems of stone material. The investigation of the relevant information showed that the economic loss caused by stone material weathering of the stone arch bridges is very great, and with the environment changing and the functional requirements increasing, the durability problems caused by weathering are more and more prominent. A large number of stone arch bridges in Chongqing is widely distributed, what is more, the harsh environment of those existed is high temperature, high humidity, acid rain deposition, long duration of sunshine, where annual evaporation is huge, climate is variable, air pollution is serious, the temperature difference between day and night is large, and the existence of chloride, sulfate and other harmful ions in some rivers, so protection of the stone arch bridges from weathering should pay more attentions. This paper commences mainly the study of weathering mechanism and experiment of the stone arch bridges, the main work conducted are as follows:①Based on field research, this paper makes the full use of existing data, solicits extensively the suggestions of transportation construction, maintenance departments and related domestic experts, and analyzes the research status of the stone material weathering of the stone arch bridge in Chongqing.②According to weathering mechanism and operating performance of a large number of stone arch bridges existed in Chongqing, this paper make the analysis of weathering mechanism based on the influence of multiple factors such as stone material composition of stone arch bridges existed in Chongqing, stone material's internal structure, erosion of the atmosphere of harmful ions, erosion of the sulphate, acid rain deposition, and bridges'construction, maintenance, operations.③This paper starts from improving the internal and external factors of stone weathering of stone arch bridges, including the effects of harmful ions in atmosphere, the sulfate ions flowed in the surface, the environment of high humidity and high temperature. The paper analyzes the mechanisms of traditional resistant weathering materials, determines the testing framework of the new type resistant weathering materials.④This paper selects the test schemes of silicone resins, acrylic resins, silicone polymers, silicone/acrylic resin physical blending and modified silicone resin or acrylic resin, in order to determine the resistant weathering materials. Those test includes the determination of tensile shear strength, the determination of adhesion force, resistance test of acid, alkali, salt, hardness measurement, contact angle measurement, the determination of water absorption, thermal performance test, and the determination of scanning electron microscopy.⑤According to Chongqing climate, this paper records the effect over time through the performance of resistant weathering materials in real bridge testing, and puts forward to the details and attention matters of design, implementation, and strengthening in resistant weathering materials of stone arch bridges in Chongqing.The results of this paper are positive significance to improve the weathering durability of stone arch bridges in Chongqing, to ensure the safety of existing stone arch bridges, to save construction funds, to accelerate the pace of highway construction and improve the quality of road construction.