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柠檬酸废渣石膏经过特殊的工艺处理可制得性能优良的α型半水石膏。利用这种α型半水膏为原料,加入一定的外加剂,可配制出优质的粉刷石膏,这种粉刷石膏粉凝结硬化块,粘结力强,有较好的保温,隔热、吸声性能,体积稳定性好、质地细腻光滑,施工方便,是一种优质的内墙抹灰材料。是对人类、环境有益的利废性建材产品。本文就利用柠檬酸废渣石膏生产粉刷石膏的生产工艺,成本及产品性能进行研究与分析。 相似文献
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《Soils and Foundations》2014,54(3):405-416
This study investigates the effect of the soaking condition in a wet environment on the stability and durability of soft clay soil treated with recycled gypsum. Cement and lime are the two types of solidification agents used to improve the durability of the clay–gypsum mixture and to reduce the solubility of the gypsum in a wet environment because gypsum is soluble in water. The recycled gypsum was mixed with cement and lime in different ratios in the dry state, and different amounts of admixtures were mixed with the tested soil to explore the effect of the wet environment on the stability and durability of the stabilised gypsum–clay soil. Cylindrical stabilised soil specimens were cured for 3, 7, and 28 days and then soaked in water for different intervals up to 60 days. The soaked samples were evaluated based on the compressive strength, durability index, deformation changes, soil deterioration, and water absorption. The results show that increasing the content of both types of admixtures had a positive effect on the improvement of stability and durability for the tested soil in a wet environment, while the increase in the admixture ratio had a slightly negative effect on both the stability and the durability of the samples subjected to soaking. Short soaking times, up to 15 days, had a negative effect on the stability, durability, and changes in volume, and brought about a deterioration in the soluble soil and the water absorption compared with longer soaking times. The short curing times of 3 and 7 days exhibited a positive effect on the improvement of the stability, strength, and durability for the stabilised specimens subjected to soaking compared with the longer curing time of 28 days. Increasing the admixture content and soaking time had a significant effect on the water absorption and the soil deterioration of the tested soil. The effect of the soaking condition on the volume changes for the soil stabilised with the two admixtures was found to be insignificant, because the maximum volume change was found to be less than 0.15%. 相似文献
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评述了欧洲、美国与日本用脱硫石膏与废石膏替代天然石膏生产纸面石膏板的进程与趋势,并由此总结出若干可供我国借鉴的主要经验。在利用脱硫石膏方面,必须确保脱硫石膏的质量;石膏板厂需对现有装备进行必要的改进;供需双方应签订长期合同;应合理择定新建石膏板厂的厂址等。在利用废石膏方面,政府应当立法;宜对收集的废弃石膏板进行集中加工并集中供货。 相似文献
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分别对C30、C50、C60不同强度等级的废旧混凝土进行破碎,筛选得到不同粒径的再生骨料,研究再生骨料的性能指标;采用聚乙烯醇与水玻璃以1∶1比例配制成不同浓度的强化液,研究强化改性对再生骨料吸水率和压碎值的影响;将再生骨料与天然骨料复配应用于混凝土中,研究其对混凝土性能的影响。结果表明:随着再生骨料掺量的增加,再生混凝土的坍落度与扩展度总体呈现先减小后增大的趋势,当再生骨料掺量在12%~24%时,再生混凝土的坍落度为200 mm左右,28 d抗压强度达到42 MPa左右。 相似文献
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为了更加清晰方便地观察并研究再生混凝土裂缝开展规律,利用模型混凝土的概念,将普通混凝土、废混凝土骨料混凝土和废砖骨料混凝土平面化,制得模型再生混凝土试件。在试件受压破坏的过程中,利用数字图像相关技术在模型混凝土前后两个表面制作不同尺度的散斑,分别用一般工业相机和显微镜相机采集图像,并分析得到全局应变场和界面过渡区附近的局部应变场,用以揭示再生混凝土裂缝开展过程和损伤演化机制。研究结果显示,废砖骨料模型再生混凝土的弹性模量最小,但是抗压强度反而比废混凝土骨料模型再生混凝土的高。废混凝土骨料模型再生混凝土全局应变场能表征应变集中位于旧砂浆区域,但不能区分新、旧界面过渡区,而局部应变场更加细致地显示裂缝首先在旧界面过渡区开展,然后新界面过渡区才有裂缝开展。对废砖骨料模型再生混凝土的分析发现,砖骨料和新砂浆之间的界面过渡区首先出现了应变集中,但是裂缝并未沿界面过渡区开展,而是贯穿了砖骨料,然后位于界面过渡区的应变集中由于应力重分布而削弱。 相似文献
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柠檬酸废渣粉刷石膏的研制 总被引:3,自引:0,他引:3
柠檬酸废渣石膏经过处理,可制得性能优良的α型半水石膏;以α型半水石膏料为原料,加入外加剂,可配制出优质的粉刷石膏。这种粉刷石膏产品凝结硬化块,粘结力强,有较好的保温、隔热、吸声性能,体积稳定性好,质地细腻光滑,施工方便,是一种优质的内墙抹灰材料。本文就利用柠檬酸废渣石膏生产粉刷石膏的生产工艺、成本及产品性能进行了研究与分析。 相似文献
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Fabiana da Conceição Leite Rosângela dos Santos Motta Kamilla L. Vasconcelos Liedi Bernucci 《Construction and Building Materials》2011,25(6):2972-2979
The wide production of construction and demolition waste and its illegal deposition are serious current problems in Brazil. This research proposes to evaluate the feasibility of using aggregate from recycled construction and demolition waste (RCDW) in pavement applications. A laboratory program was conducted by geotechnical characterization, bearing capacity and repeated load triaxial tests. The results show that the composition and the compactive effort influence on the physical characteristics of the RCDW aggregate. The compaction process has promoted a partial crushing and breakage of RCDW particles, changing the grain-size distribution and increasing the percentage of cubic grains. This physical change contributes to a better densification of the RCDW aggregate and consequently an improvement in bearing capacity, resilient modulus and resistance to permanent deformation. The results have shown that the RCDW aggregate may be utilized as coarse base and sub-base layer for low-volume roads. 相似文献
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介绍了废弃混凝土再生骨料是建筑产品高度发展的结果,通过对废弃混凝土的有效处理,解决了建筑垃圾给环境带来的污染问题,提高了再生混凝土骨料的使用价值,对利用再生骨料的企业具有十分重要的借鉴意义. 相似文献
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为了研究废弃纤维体积掺量和长度、再生骨料掺入量及水灰比对废弃纤维再生混凝土力学性能的影响,采用棱柱本试件与刚性元件组合的方法,测定了废弃纤维再生混凝土的应力-应变全曲线.试验表明:废弃纤维可以明显提高再生混凝土的轴心抗压强度.废弃纤维再生混凝土的峰值应变随着水灰比、废弃纤维长度、废弃纤维体积掺量和再生骨料掺量的增加而增大;峰值应力随着水灰比和再生骨料掺入量的增加而减小.当废弃纤维长度为19mm、体积掺量为0.16%时,轴心抗压强度相对于普通再生混凝土的提高幅度最大.废弃纤维再生混凝土的应力-应变曲线分为上升段和下降段,通过拟合相关参数,提出了应力-应变全曲线方程用分段有理分式表达,拟合结果与试验数据较吻合. 相似文献
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磷石膏废物资源化利用浅析 总被引:1,自引:0,他引:1
在人口膨胀、资源相对短缺、生态环境恶化的今天,废物综合利用已成为改善人类生存环境、保障社会经济持续发展的方式之一。本着节省资源、改善生态环境、丰富建筑材料品种的目的,各国在磷石膏废物资源化利用方面不懈地开展着研究。本文从磷石膏的特点着手,综述了国内外磷石膏资源化利用的情况。 相似文献
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利用建筑垃圾生产混凝土的性能研究 总被引:1,自引:0,他引:1
通过对再生骨料基本性能的研究,根据再生骨料的特殊物理性能,设计研究了不同级配下的再生骨料混凝土的工作性能和抗压强度.当细骨料采用天然砂,级配合理时,再生混凝土28 d抗压强度可以达到44 MPa,工作性能良好;当粗细骨料都采用再生骨料,再生骨料的粒径分布为0~5 mm约占60%~70%,5~10mm约占30%~40%时,可以满足配制强度为15MPa再生混凝土的要求,粗、细骨料的重量比达到50%以上时再生混凝土的工作性比较好、强度可以达到12.4~14.9 MPa. 相似文献
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建筑固废的处理再利用是使得建筑垃圾资源化的重要措施。为了进一步推进建筑固废动力特性的研究和工程应用,以建筑固废破碎筛分后的再生细骨料为材料,制备成地基土试样。利用三轴动力测试,分析了排水条件下,不同级配(级配良好、级配较差)、相对密度Dr(45%、70%)、围压σc(25、50、100、200 kPa和400 kPa)和含水率(0%、5%、15%、25%和30%)对再生细骨料地基动力特性的影响,并与标准砂地基的动力特性进行对比分析。试验结果表明:再生细骨料的比重为1.912,小于标准砂的(2.65),使得再生细骨料试样动剪切模量小于标准砂的;阻尼比在剪应变γ较小(γ<0.03%)时与标准砂的差别不大,而剪应变较大(γ>0.03%)时小于标准砂的;在四个影响因素中,围压的变化对动剪切模量的影响最大,围压增大时,动剪切模量明显增大,其次影响较大的是相对密度以及含水率,级配的影响相对最小。通过对可破碎性的分析发现,再生细骨料在小围压(σc<200 kPa)条件下基本未发生破碎,即使在围压为400 kPa、等效循环应力比rcs为0.3的条件下也只发生了少量破碎,此破碎量符合国家标准。 相似文献
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建筑垃圾再生混凝土耐久性能的研究 总被引:2,自引:0,他引:2
本文研究了建筑垃圾再生混凝土的收缩、抗碳化、抗氯离子渗透、抗冻融等性能。研究结果表明再生混凝土试块收缩较大,抗碳化和抗氯离子渗透性能中等,但抗冻融性较差。通过掺加粉煤灰和高效减水剂,降低水胶比可以提高再生混凝土的耐久性能。 相似文献
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The main purpose of this research is to develop a calculation method to assess the probability of liquefaction and a reliability-based design method to mitigate the liquefaction in sandy grounds. The probability of liquefaction is evaluated with the proposed model by considering the spatial variability of the soil parameters and the statistical characteristics related to the occurrence of earthquakes. The liquefaction resistance is calculated from the SPT N-value, the median grain size, D50, and the fines content, Fc, through the empirical relationship [Iwasaki T, Arakawa A, Tokida, K. Simplified procedure for assessing soil liquefaction during earthquakes. Proc Soil Dyn Earthquake Eng Conf 1982;925–39]. The statistical models for these three soil parameters are determined with the maximum likelihood method. The occurrences of earthquakes is modeled based on the maximum annual acceleration found in historical earthquake data records. In this study, the probability of liquefaction is evaluated multi-dimensionally using the cokriging method. Finally, the reliability-based design method is discussed in order to determine the optimum design for ground improvement using sand compaction piles (SCP) based on the calculated probability of liquefaction. 相似文献
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再生混凝土的耐久性及其改善措施 总被引:9,自引:4,他引:9
在大量文献研究的基础上,本文较为全面地综述和分析了再生混凝土的耐久特征及其改善措施,主要包括再生混凝土的抗渗性、抗冻融性、抗硫酸盐侵蚀性、碳化以及氨离子渗透性和耐磨性。研究表明,总体来讲,再生混凝土的耐久性较普通混凝土差。但是,通过减小水灰比、掺加粉煤灰、采用二次搅拌工艺、减小再生骨料最大粒径和采用半饱和状态的再生骨料等措施可以改善再生混凝土的耐久性。最后,提出了关于再生混凝土耐久性需要进一步研究的问题。 相似文献