CAJ | 학술논문

碳化混凝土的复碱化是用碳酸钙缓冲溶液浸渍混凝土的电化学过程,目的是使混凝土孔溶液的pH值稳定在10以上,从而防止混凝土的进一步碳化.然而,该方法的实际应用表明:虽然孔溶液中已明显含有足量的碱(Na+,K+,Li+),但pH值仍降到10以下.本文通过试验提出了一个用以解释pH值随时间降低的假说,结果表明:由于混凝土孔溶液中存在溶解的硫酸盐,因此单纯提高孔溶液的碱离子(碳酸盐)相对含量,不能确保其pH值高于10.用提出的化学机理可解释混凝土电化学复碱化技术实际应用中观察到的现象,但是,由于混凝土孔溶液中溶解离子相互作用十分复杂,目前还不能在复碱化技术中对其加以考虑,因此复碱化技术尚不能被进一步推荐应用.
탄화혼응토적복감화시용탄산개완충용액침지혼응토적전화학과정,목적시사혼응토공용액적pH치은정재10이상,종이방지혼응토적진일보탄화.연이,해방법적실제응용표명:수연공용액중이명현함유족량적감(Na+,K+,Li+),단pH치잉강도10이하.본문통과시험제출료일개용이해석pH치수시간강저적가설,결과표명:유우혼응토공용액중존재용해적류산염,인차단순제고공용액적감리자(탄산염)상대함량,불능학보기pH치고우10.용제출적화학궤리가해석혼응토전화학복감화기술실제응용중관찰도적현상,단시,유우혼응토공용액중용해리자상호작용십분복잡,목전환불능재복감화기술중대기가이고필,인차복감화기술상불능피진일보추천응용.
Method for realkalisation of carbonated concrete is based on the electrochemicalprocesses. In order to increase the pH value of pore solution the concrete is impregnated withalkali carbonates solutions. These buffer solutions should stabilize the pH value of pore solu-tion at a level higher than 10. However, analyses of impregnated concrete in practice showthat the pH value drops to values below 10 although sufficient alkali (Na+ , K+ , Li+ ) con-centration was available in pore solution. Experiments were carried out to confirm a hypothe-sis to explain the time-dependent decrease of the pH value. It is concluded that in the pres-ence of dissolved sulfates even a comparatively high content of alkali carbonates is not suffi-cient to maintain pH value higher than 10. The chemical mechanisms suggested in this paperare used to explain observations of practical applications. The complex interactions of dis-solved ions in pore solution have hardly been taken into consideration of the development ofnew technologies for realkalisation up to now. For this reason, the methods for realkalisationof carbonated concrete as discussed in this paper cannot be recommended.