CAJ | 학술논문

通过低气压试验箱模拟高原不同海拔地区气压环境，研究了环境气压对引气剂引气能力的影响。试验结果表明：环境气压的降低将显著削弱引气剂的引气能力，当环境气压降低至50 kPa时，混凝土含气量降低约20％～49％；混凝土含气量随环境气压降低呈线性减少，初始含气量越高，随环境气压降低含气量减少速率越大；混凝土坍落度越大，其抵抗因环境气压降低造成含气量降低的能力越强。因此，在高原地区设计引气混凝土时应针对不同结构物，结合当地气压条件及引气剂类型，相较于常压情况适当增加引气剂掺量，以达到抗冻设计指标中要求的含气量。
통과저기압시험상모의고원불동해발지구기압배경，연구료배경기압대인기제인기능력적영향。시험결과표명：배경기압적강저장현저삭약인기제적인기능력，당배경기압강저지50 kPa시，혼응토함기량강저약20％～49％；혼응토함기량수배경기압강저정선성감소，초시함기량월고，수배경기압강저함기량감소속솔월대；혼응토담락도월대，기저항인배경기압강저조성함기량강저적능력월강。인차，재고원지구설계인기혼응토시응침대불동결구물，결합당지기압조건급인기제류형，상교우상압정황괄당증가인기제참량，이체도항동설계지표중요구적함기량。
The effect of air pressure of environment on air content of fresh concrete was studied using low-pressure test chamber to stimulate the plateau environment.The experimental results indi-cate that the air pressure of environment has a significant impact on the performance of air-entraining agents.The air content of fresh concrete falls by roughly 20% to 49% when the air pressure is 50 kPa.The air content of fresh concrete decreases linearly with the drop of air pressure.The higher the air content of fresh concrete mixed in ordinary pressure,the faster the air content of fresh concrete decreases with the drop of air pressure.The concrete with high slump shows better resistance to drop of air-content due to low air pressure than the concrete with low slump.Therefore,in order to meet the design requirements of air content of air-entrained concrete for different constructions in the plat-eau regions,it is necessary to increase the dosages of air-entraining agents according to different pressure conditions and types of air-entraining agent.