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Title |
Deterioration Properties of Shotcrete as Tunnel Supporter was Exposed to Harmful Ions
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Keywords |
화학적침식 ; 열화 ; 유해이온 ; 숏크리트 ; 외관조사 ; X-ray 분석 Chemical attack ; Deterioration ; Harmful ions ; Shotcrete ; Visual examination ; XRD |
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Abstract |
Shotcrete have become a deterioration which was exposed to harmful environments. In this study, in order to evaluate the deterioration properties of shotcrete, visual examination, compressive strength, adhesive strength, microstructural analysis were investigated up to the 60th weeks of exposure. The attack solutions for test are sodium sulfate and hydrochloric acid solution with different concentrations, respectively. From the results, although the compressive strength of shotcrete specimens and the adhesive strength between specimens and rocks were high at the early immersion age, they rapidly dropped in the subsequent phases, especially in 5% sodium sulfate and pH1 hydrochloric acid solution. With continued exposure, various harmful ions penetrated into the shotcrete specimen, reacted with the cement hydrate, and generated expansion substances. It was verified that the shotcrete specimens suffered a serious deterioration by chemical attack.
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