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魏    威

（ 中鐵十九局集團華東工程有限公司 ，浙江 余姚 315400)

摘   要 ：將研磨后的鐵尾礦粉末和硅粉分別按照 3 ∶ 2 和4 ∶ 1 的比例制備了兩種復(fù)合礦物摻合料替代水泥進行漿體和混凝土試樣的制備 。通過微觀結(jié)構(gòu)分析 、強度和耐久性分析對鐵尾礦－硅粉復(fù)合礦物摻合料漿體和混凝土的基本性能進行了研究，結(jié)果表明 ：隨著復(fù)合礦物摻合料摻量的增加，試樣的水化反應(yīng)放熱量、抗壓強度、 劈裂抗拉強度和凍融耐久性均逐漸降低 ；且加入鐵尾礦粉可使的硬化漿體試塊孔隙結(jié)構(gòu)變大，導(dǎo)致混凝土的抗  壓強度和凍融耐久性降低 ；但增加硅粉的摻量可以提高試樣的水化反應(yīng)強度 ，降低 Ca  ( OH) 2 的含量，且硅粉水化反應(yīng)生產(chǎn)的 C - S- H 凝膠也可以細化孔結(jié)構(gòu) ，從而改善混凝土的微觀特性 、抗壓強度 、劈裂抗拉強度和凍融耐久性 ；彌補鐵尾礦粉對混凝土性能的負面影響 。整體上 ，改性混凝土的抗壓強度在普通混凝土抗壓強的 85%以上，能滿足工程要求。

關(guān)鍵詞 ：鐵尾礦粉 ；硅粉 ；混凝土 ；水化特征 ；微觀結(jié)構(gòu) ；強度 ；凍融耐久性

中圖分類號 ：TU528           

文獻標志碼 ：A            

文章編號 ：1005- 8249  (2023)   06- 0041- 07

DOI : 10. 19860/j . cnki . issn1005- 8249. 2023 . 06. 007

 

WEI Wei

( China Railway  19th Bureau Group East China Engineering Co. ，Ltd. ，Yuyao 315400 ,   China)

Abstract :  Two kinds of composite mineral admixtures were prepared by grinding iron tailings powder and silicon powder in the ratios of 3:2 and 4:1, respectively to substitute cement for the preparation of mortar and concrete samples.The basic properties of iron tailings-silica fume composite mineral admixture mortar and concrete have been studied through microstructure analysis, strength and durability analysis. The results show that: As the content of the composite mineral admixture increases, the heat of hydration reaction, compressive strength, split tensile strength and freeze-thaw durability of the sample gradually decrease; and adding iron tailings powder can increase the pore structure of the hardened mortar test block, which reduces the compressive strength and freeze-thaw durability of the concrete. However, increasing the amount of silica fume can increase the strength of the hydration reaction of the sample, and increasing the silica fume can reduce the content of Ca(OH)₂. The CSH gel produced by the hydration reaction of silica fume can also refine the pore structure, thereby Improve the microscopic properties, compressive strength, split tensile strength and freeze-thaw durability of concrete; make up for the negative impact of iron tailings powder on concrete performance. On the whole, the compressive strength of modified concrete is more than 85% of that of ordinary concrete, which can meet engineering requirements.

Keywords :  iron tailings powder;   silica fume ,   concrete ;  hydration characteristics ;  microstructure ,   strength;  freeze-thaw durability

作者簡介 ：魏威  ( 1985—) ,   男 ，高級工程師 ，主要研究方向 ：公路橋梁施工建設(shè)。

收稿日期 ：2023- 06-23