Abstract

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Title:: Experiment on Durability Damage Assessment of Concrete Field Exposed in Saline Soil Area of Ningxia

Author(s):: QIAO Hong-xia; LU Cheng-gong; LI Yu; GUAN Li-juan; Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province, Lanzhou University of Technology

Keywords:: concrete; field exposure; saline soil; durability; damage assessment; sulfate erosion

Abstract:: The concrete specimens with different amounts of fly ash were taken as research object. The concrete specimens of three kinds of mix ratio were exposed to saline soil with typical characteristics in Ningxia area. The relative mass and relative dynamic elastic modulus were selected as evaluation parameters. Through the comparative analysis, the more suitable comprehensive damage assessment parameters of durability evaluation of the concrete field exposed in the saline area were obtained. At the same time, the degradation mechanism of concrete under sulfate erosion in saline soil was studied combining with microcosmic analysis of field exposed concrete. The reasons for the durability change of concrete in saline soil area were analyzed from micro perspective. The results show that the concrete is subjected to complex chemical erosion in the saline soil area, and react with sulfate in soil to form calcium sulphoaluminate crystals which is filled in the pore. The durability of concrete in saline soil area can be well described by the comprehensive damage assessment parameters.