【摘要】：青藏高原高海拔的多年凍土區(qū)巖土工程，都面臨著高溫、高含冰凍土以及全球氣候變暖的難題。工程修建帶來的人工熱擾動(dòng)必將導(dǎo)致下部多年凍土融化沉降，尤其對(duì)于未來黑色路面的高速公路更為嚴(yán)重。這樣給維持多年凍土區(qū)工程長(zhǎng)期安全增加了難度，隨之而來的還有病害治理問題。本文在課題組前期相關(guān)富水熱半導(dǎo)體材料研究成果基礎(chǔ)上，新研制一種既可以在新建路基中應(yīng)用，又可治理既有路基工程的新型高效、施工方便、經(jīng)濟(jì)環(huán)保熱半導(dǎo)體材料。此種新型富水材料基于冰、水相變后的4倍導(dǎo)熱系數(shù)差異，水化反應(yīng)形成的網(wǎng)狀結(jié)構(gòu)可短時(shí)間固結(jié)大量自由水，，凍融狀態(tài)下導(dǎo)熱系數(shù)比在2.9倍以上，并形成較高的強(qiáng)度。 本文以室內(nèi)試驗(yàn)為主，選用硫鋁酸鹽水泥熟料為基料，天然硬石膏和生石灰為輔料，考慮多種添加劑同時(shí)作用的復(fù)雜性和攪拌工藝的影響，通過正交優(yōu)化，最終確定新型富水熱半導(dǎo)體材料的制漿工藝為：基料漿液和輔料漿液分別攪拌5min后混合澆筑；各組分配比范圍為：以硫鋁酸鹽水泥熟料為基料，緩凝劑R1和緩凝劑R2（0.4%~0.6%，與基料的質(zhì)量比，下同）、基料膨潤(rùn)土（2%~4%）、天然硬石膏（40%~60%）、生石灰（15%~25%）、氫氧化鋰（2%~4%）、促凝劑C（2%~4%）、輔料膨潤(rùn)土（5%~7%）。獲得研制的新型熱半導(dǎo)體材料性質(zhì)如下： (1)新型富水材料在水灰比為2.0~3.0條件下，含水率達(dá)到140%以上，凍融狀態(tài)下導(dǎo)熱系數(shù)比分別為2.9倍以上，養(yǎng)護(hù)28d抗壓強(qiáng)度大于1.7MPa，并且其凍脹率和滲透系數(shù)分別低于3.9%和9.6E-6cm/s。 (2)對(duì)新型富水材料試樣進(jìn)行25次凍融循環(huán)測(cè)試，得出水灰比2.0、2.5和3.0試樣的保水率和抗壓強(qiáng)度分別在97%和1.3MPa以上，水灰比2.0試樣的強(qiáng)度高達(dá)2.94MPa。在經(jīng)歷多次凍融后，保水率較高，具有良好的熱半導(dǎo)體性，抗壓強(qiáng)度保持在峰值強(qiáng)度的80%以上，新型富水材料具有良好的抗凍融性。 (3)在不改變材料熱半導(dǎo)體性的同時(shí)，利用其重結(jié)晶性質(zhì)，確定了材料的預(yù)壓荷載為對(duì)應(yīng)臨期峰值強(qiáng)度的80%，將三種水灰比試樣養(yǎng)護(hù)3d后進(jìn)行預(yù)壓處理，其后續(xù)強(qiáng)度均有所增大，水灰比3.0試樣強(qiáng)度可提高近10%，且水灰比越大預(yù)壓時(shí)間越早，后續(xù)強(qiáng)度增長(zhǎng)越大。因此，工程應(yīng)用時(shí)合理利用材料的重結(jié)晶性，能有效提高材料的抗壓強(qiáng)度，加強(qiáng)工程的力學(xué)穩(wěn)定性。 綜合試驗(yàn)結(jié)果，新型富水熱半導(dǎo)體材料具有富水、高熱半導(dǎo)體性、高強(qiáng)、低凍脹和低滲五大特性，并具有良好的抗凍融循環(huán)特性，是一種針對(duì)多年凍土區(qū)巖土工程理想的熱半導(dǎo)體漿液材料。
[Abstract]:Geotechnical engineering in permafrost areas of Qinghai-Xizang Plateau is faced with the problems of high temperature, high ice content, frozen soil and global warming. The artificial thermal disturbance caused by engineering construction will lead to the melting and settlement of permafrost in the lower part, especially for the highway with black pavement in the future. This makes it more difficult to maintain the long-term safety of permafrost engineering, followed by the problem of disease control. On the basis of the research results of hydrothermal semiconductor materials in the early stage of the research group, a new type of high efficiency, convenient construction and economic and environmental protection thermal semiconductor materials can be developed, which can not only be used in the new roadbed, but also can be used in the treatment of the existing subgrade engineering. Based on the difference of thermal conductivity of ice and water phase transformation, the reticular structure formed by hydration reaction can consolidate a large amount of free water in a short time, and the thermal conductivity ratio is more than 2.9 times in freeze-thaw state, and the strength is higher. In this paper, based on laboratory test, sulphoaluminate cement clinker is selected as base material, natural anhydrite and quicklime as auxiliary materials, considering the complexity of simultaneous action of various additives and the influence of mixing process, through orthogonal optimization, Finally, the pulping process of the new hydrothermal semiconductor material is determined as follows: the base slurry and auxiliary slurry are mixed and poured with 5min respectively; The distribution ratio of each group is as follows: using sulphoaluminate cement clinker as base material, retarder R1 and retarder R2 (0.4% 鈮

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