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（中鐵十八局集團(tuán)第二工程有限公司，  唐山 063000）

［摘要］以高海拔大溫差地區(qū)兩河口水電站木絨大橋?yàn)槔?，研究粉煤灰、硅粉及引氣劑摻量?duì)C60機(jī)制砂泵送混凝土工作性能、抗壓強(qiáng)度、抗凍性能和微觀形貌的影響。結(jié)果表明，粉煤灰有利于增加混凝土的坍落度、擴(kuò)展度和抗氯離子滲透性能，不利于早期7d強(qiáng)度和抗碳化性能，但后期56d強(qiáng)度增加顯著；硅粉會(huì)增加混凝土的強(qiáng)度，尤其是早期強(qiáng)度增加顯著，28d強(qiáng)度達(dá)到79-5MPa，還會(huì)提高混凝土的抗碳化能力和抗氯離子滲透能力；引氣劑可以減少膠凝材料總量，改善和易性，提高抗氯離子滲透能力，大量增加直徑20nm以下的無(wú)害孔數(shù)量，從而有效改善混凝土抗凍融破壞能力。木絨大橋高品質(zhì)機(jī)制砂C60泵送混凝土的抗裂等級(jí)為Ⅱ級(jí)，抗裂性良好。

［關(guān)鍵詞］高品質(zhì)機(jī)制砂； C60混凝土； 高海拔； 抗凍性能

中圖分類(lèi)號(hào)：TU528-31文獻(xiàn)標(biāo)識(shí)碼：A文章編號(hào)：1002-848X(2019)12-0109-06

Application of C60 machine-made sand pumped concrete in cantilever beam of Murong Bridge of Lianghekou Hydropower Station

Li Huimin

（China Railway Eighteenth Bureau Group Second Engineering Limited Company， Tangshan 063000， China）

Abstract:The Murong Bridge of Lianghekou Hydropower Station in high altitude and large temperature difference area was taken as an example to study the effects of fly ash, silicon powder and air-entraining agent on the working performance, compressive strength, frost resistance and micro-morphology of C60 machine-made sand pumped concrete. The results show that fly ash is beneficial to increase slump, expansion and chloride ion penetration resistance of concrete, and is not conducive to the early 7d strength and carbonation resistance, but its later 56d strength increases significantly. Silicon powder can increase the strength of concrete, especially the early strength, which reaches 79-5MPa in 28d strength, and silicon powder also improve the carbonation resistance and chloride ion penetration resistance of concrete. Air entraining agent can reduce the total amount of cementing materials, improve the workability, improve the resistance to chloride ion penetration, and increase the number of harmless holes less than 20nm in diameter, so as to effectively improve the frost resistance of concrete. The crack resistance grade of high-quality C60 machine-made sand pumped concrete for Murong Bridge is grade Ⅱ, and the crack resistance is good.

Keywords:high-quality machine-made sand; C60 concrete; high altitude; frost resistance

*國(guó)家自然基金面上項(xiàng)目（51678049）。

作者簡(jiǎn)介：李惠民，學(xué)士，高級(jí)工程師，Email:578264391@qq.com。