摘要
高性能轻骨料 (HPLWA)强度高而吸水率低 ,即使在负压或正压条件下 ,吸水率仅 5 %左右 ,而表观密度为0 9kg/m3 的HPLWA比 1 2 g/cm3 具有更低的吸水率 ;普通轻骨料 (NLWA)则比较敏感 ,特别在负压或正压条件下 ,吸水率高达 40 %以上。对于表观密度为 1 2g/cm3 的HPLWA ,即使不预先湿水 ,所配制的混凝土 ,在 1 5小时内仍能满足泵送所需要的坍落度要求。对于NLWA ,则必须在负压或正压下预湿处理 ,方可使其坍落度在 90分钟内保持泵送所需要的坍落度 ,但此处理对于混凝土的强度是不利的。而常压泡水 30分钟 ,对HPLWAC和NLWAC的强度均无不利影响。
? High performance lightweight aggregate (WA) has disconnected spherical pores, low water absorption and high compressive strength. It reaehed the saturation state within several minutes under atmospheric pressure or vacuum,and the vacuum saturation was just 2～3% higher than the atmospheric absorption. Normal lightweight aggregate (LWA) was more sensitive than HPLWA to the increase in pumping pressure or pumping distance/height in another sense. Of the two HPLWA's with difference in particle density only, the one with particle density of 0 9 kg/m\+3 performed better in resistance to water penetration than the other one with particle density of 1 2kg/m\+3. Slump of oncrete with none pre soaked HPLWA could be kept without much loss for 1.5hr, so it is not necessary to pre soak HPLWA for pumping. Even having been pre soaked, normal LWA in concrete would still absorb much more water than HPLWA under pumping pressure. Vacuum saturation had an adverse effect on strength of normal LWA concrete at later ages, while submersion in water for 30 minutes did not influence the strength of concrete with normal LWA or HPLWA at all. 〔
出处
《混凝土》
CAS
CSCD
2001年第6期49-52,共4页
Concrete
关键词
轻骨料吸水特性
真空吸水
压力吸水
轻骨料混凝土
流动性
泵送性
抗压强度
water absorption of lightweight aggregate
water absorption under vaeuum
water absorption under pressure
Lightweight aggregate concrete
slump
pumping
strength
