(中國礦業(yè)大學(xué)(北京) 能源與礦業(yè)學(xué)院，北京 100083)
摘 要: 為探究干濕循環(huán)過程對全尾砂固結(jié)體力學(xué)性質(zhì)的損傷作用，系統(tǒng)研究了干濕循環(huán)作用對全尾砂固結(jié)體單軸抗壓強度的劣化規(guī)律，并結(jié)合壓汞儀、掃描電鏡和熱重分析裝置等測試儀器分析了干濕循環(huán)作用對全尾砂固結(jié)體的損傷機理。結(jié)果表明：養(yǎng)護3 d的全尾砂固結(jié)體在干濕循環(huán)作用下單軸抗壓強度呈先上升后降低趨勢，在干濕循環(huán)初期，固結(jié)體內(nèi)部生成更多的水化產(chǎn)物，孔隙減少，整體結(jié)構(gòu)更加致密；隨干濕循環(huán)的繼續(xù)進行，固結(jié)體逐漸破壞。養(yǎng)護28 d的固結(jié)體強度隨干濕循環(huán)次數(shù)的增加逐漸降低，水泥含量越高，固結(jié)體強度的降幅越低；未經(jīng)干濕循環(huán)的試件內(nèi)部孔隙少，水化產(chǎn)物層狀疊加；在干濕循環(huán)作用下，水化產(chǎn)物之間的連接逐漸破壞，孔隙率由35.75%增加至39.08%，且大孔占比大幅度上升。干濕循環(huán)作用引起的顆粒脹縮和水侵蝕導(dǎo)致固結(jié)體內(nèi)部出現(xiàn)更多孔隙，部分孔隙聯(lián)通形成大孔，水化產(chǎn)物減少，從而使固結(jié)體內(nèi)部結(jié)構(gòu)變得松散破碎，這是導(dǎo)致固結(jié)體損傷的主要原因。
關(guān)鍵字: 全尾砂固結(jié)體；干濕循環(huán)；孔隙；水化產(chǎn)物；損傷
（School of Energy and Mining, China University of Mining and Technology (Beijing), Beijing 100083, China）
Abstract:In order to explore the damage effect of the dry-wet cycle process on the mechanical properties of the whole tailings consolidation, the degradation of the uniaxial compressive strength of the total tailings consolidated by the dry-wet cycle was systematically studied, combined with mercury intrusion testing and scanning electron microscopy. Test methods, such as thermogravimetric test and other test methods, were used to analyze the damage mechanism of the whole tailings consolidation by the dry-wet cycle. The results show that the uniaxial compressive strength of the whole tailings consolidated body cured for 3 d under the action of the dry-wet cycle increases first and then decreases. At the beginning of the dry-wet cycle, more hydration products are generated in the consolidated body and the pores decrease. The overall structure is more compact, and the consolidated body is gradually destroyed as the dry-wet cycle continues. The strength of the consolidated body cured for 28 d gradually decreases with the increase of the number of dry-wet cycles. The higher the cement content, the lower the decrease. The internal pores of the specimens without the dry-wet cycle are less, and the hydration products are layered. Under the action of the dry-wet cycle, the connection between the hydration products is gradually broken, the porosity increases from 35.75% to 39.08%, and the proportion of macropores increases greatly. The dry-wet cycle causes the particles to expand and shrink, which leads to more pores in the consolidation body. The erosion of water and the generation of cracks lead to the increase of pores in the consolidation body and the formation of macropores, and the reduction of hydration products makes the interior structure of the consolidation body loose and broken, which is the main reason that causes the consolidated body damaged.
Key words: total tailings consolidation; dry-wet cycle; pores; hydration products; damage
