热压成型与冷压成型粉煤灰基试块特性研究  

Study on Property of Concrete Block Based on Fly Ash Under the Condition of Hot-pressing and Rom Temperature-pressing

作　　者：段思宇[1] 廖洪强[1] 程芳琴[1] 张金才[1] 刘勇 

机构地区：[1]国家环境保护煤炭废弃物资源化高效利用技术重点实验室,煤电污染控制及废弃物资源化利用山西省重点实验室,山西大学资源与环境工程研究所,山西太原030006

出　　处：《粉煤灰综合利用》2016年第5期16-20,共5页Fly Ash Comprehensive Utilization

基　　金：国家科技支撑计划项目(2013BAC14B05);山西省煤基重点科技攻关项目(MC2014-06)

摘　　要：试验研究了热压(120℃、20MPa)与冷压(20℃、20MPa)成型方法对粉煤灰基试块抗压强度的影响。采用XRD、FT-IR、SEM、TGA分析手段,分别对两种试块的矿物组成、成键结构、微观形貌和热失重特性进行对比分析。结果表明,热压成型试块的抗压强度是冷压成型的2.5倍;与冷压成型试块相比,热压试块的XRD谱图中检测出更加明显的硅铝酸盐水化产物衍射峰;FT-IR谱图中的[SiO_2]吸收峰强弱为:粉煤灰原样>冷压成型试块>热压成型试块;热压试块SEM图片中的颗粒痕迹更加模糊,有更为大量的絮状物微观形貌,且能谱中的钙硅原子比(Ca/Si)约为0.7,该比值为冷压型块的近1/3;热压和冷压试块的自由水失重率分别为3.0%和4.5%,硅铝酸盐水化物失重率分别为1.2%和0.3%。说明粉煤灰基热压成型试块较冷压成型试块具有更加明显和更加深刻的水化反应。Compressive strength of concrete block based on fly ash were tested under the condition of hot- pressing（ 120℃ and 20MPa） and room temperature- pressing（ 20℃ and 20MPa）. Some properties of the tow concrete blocks were analyzed by some analyzers of XRD,FT- IR,SEM and TGA,and these properties included the mineral compositions,chemical bonding structure,microstructure features and thermal weight loss characteristics,respectively. The testing results indicated that the compressive strength of hot- pressing block is about 2. 5 times more than that of the room temperature- pressing block. In XRD spectrum,more enhanced diffraction peaks of aluminum- silicate hydrates from the hot- pressing block were detected comparing that of room temperature- pressing. In FT- IR spectrum,the order of the absorption peak strength for [SiO_2]bond from the three samples was fly ash room temperature- pressing block hot- pressing block. The pictures from SEM showed that more fuzzy particle traces and more floc micro- morphology for the hot- pressing block was observed than that of room temperature- pressing,and the atom ratio of calcium and silicon from the hot- pressing blocks was nearly 1 /3 of that from room temperature- pressing block. TG / DTG plot showed that the contents of free water weight in the hot- pressing block and in the room temperature- pressing block were 3. 0% and 4. 5%,and the contents of aluminum- silicate hydrates weight were 1. 2% and 0. 3%,respectively.

关 键 词：粉煤灰 强度 XRD FT-IR SEM TG 

分 类 号：TU522.35[建筑科学—建筑技术科学]