【摘要】：通過低氣壓試驗箱模擬高原不同海拔地區(qū)氣壓環(huán)境,研究了低氣壓環(huán)境對引氣混凝土含氣量及氣泡穩(wěn)定性的影響。結(jié)果表明:環(huán)境氣壓的降低能夠顯著削弱引氣劑的引氣能力,混凝土含氣量隨環(huán)境氣壓降低呈線性減少,當(dāng)環(huán)境氣壓降低至50 k Pa時,混凝土含氣量比常壓環(huán)境下降低約28%~52%。低氣壓環(huán)境使引氣混凝土氣泡穩(wěn)定性變差,在攪拌結(jié)束50~55 min內(nèi),低壓引氣混凝土含氣量經(jīng)時損失較大,且氣泡間距系數(shù)明顯增大;延長振搗時間會使低壓引氣混凝土損失更多氣泡,從而導(dǎo)致含氣量降低幅度以及間距系數(shù)的增大程度均大于常壓引氣混凝土。
[Abstract]:The influence of low pressure environment on the air content and bubble stability of air-entrained concrete was studied by simulating the atmospheric pressure environment in different altitude areas of the plateau by means of a low pressure test box. The results show that the air content of concrete decreases linearly with the decrease of ambient pressure. When the ambient pressure is reduced to 50 k Pa, the air content of concrete decreases about 28% and 52% than that under normal pressure. In the low pressure environment, the bubble stability of the air-entrained concrete becomes worse. Within 50 ~ 55 min after stirring, the air content of the low-pressure air-entrained concrete is larger and the bubble spacing coefficient is obviously increased. Prolonging the vibrating time will lead to the loss of more bubbles in low-pressure air-entrainment concrete, which will result in the decrease of air content and the increase of the spacing coefficient of air-entrainment concrete, which is larger than that of atmospheric air-entrained concrete.
【作者單位】： 交通運(yùn)輸部公路科學(xué)研究院;東南大學(xué)交通學(xué)院;
【基金】：國家自然科學(xué)基金(51308246)資助項目 交通運(yùn)輸部科技(201231879210)資助項目
【分類號】：TU528

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相關(guān)期刊論文 前5條

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本文編號：2250645