碱激发风积沙混凝土力学性能与孔隙结构特征  

Mechanical Properties and Pore Characteristic of Alkali-Activated Aeolian Sand Concrete

作　　者：郭晓松 邹春霞[1] 薛慧君[1] 徐德儒 孙浩然 丁峰 GUO Xiaosong;ZOU Chunxia;XUE Huijun;XU Deru;SUN Haoran;DING Feng(Water Conservancy and Civil Engineering College,Inner Mongolia Agricultural University,Hohhot,010018,China;Inner Mongolia Hetao Irrigation District Drainage Management Bureau,Bayan Nur,015000,China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,呼和浩特010018 [2]内蒙古河套灌区排水事业管理局,内蒙古巴彦淖尔015000

出　　处：《工业建筑》2022年第11期162-168,共7页Industrial Construction

基　　金：内蒙古自治区水利科研专项项目(NSK2016-S11);内蒙古自然科学基金项目(2022MS05043);内蒙古农业大学引进优秀博士人才科研启动资助项目(NDYB2018-40)。

摘　　要：为探究常温养护下碱激发作用对风积沙混凝土力学性能的影响,选取库布齐沙漠风积沙等质量代替河砂(40%),采用NaOH作为激发剂制备碱激发风积沙混凝土。通过抗压强度试验、核磁共振试验研究常温养护下风积沙混凝土抗压强度和孔隙变化规律,并引入灰熵关联度和灰色模型进行分析,建立了NaOH激发风积沙混凝土抗压强度模型。结果表明:常温养护下,随着NaOH掺量的增加,风积沙混凝土抗压强度呈先增加后减小,孔隙度呈先减小后增加;且5%NaOH掺量时风积沙混凝土抗压强度平均增长率最高,28 d最高达51.02 MPa,孔结构最优。5%NaOH激发40%粉煤灰风积沙混凝土28 d的抗压强度与普通20%粉煤灰风积沙混凝土相当,孔结构更优,可有效提高粉煤灰利用率,减少水泥用量。进一步,基于灰熵关联度建立了抗压强度GM(1,2)预测模型,预测值和试验值平均相对误差为1.96%和1.34%,精度较高。In order to explore the influence of alkali excitation on the mechanical properties of aeolian sand concrete under normal temperature curing, this study selected the Kubuqi Desert aeolian sand instead of river sand(40%), and using NaOH as the activator to configure alkali-activated aeolian sand concrete. Through compressive strength test and nuclear magnetic resonance test, the compressive strength and pore change law of aeolian sand concrete under normal temperature curing were studied. By introducing grey entropy correlation degree, the compressive strength model of alkali activated aeolian sand concrete was established. The results showed that under normal temperature curing, with the increase of NaOH content, the compressive strength of aeolian sand concrete first increased and then decreased. The porosity first decreased and then increased. The average increase rate of compressive strength of aeolian sand concrete was the highest when 5% NaOH was added, up to 51.02 MPa at 28 d, the pore structure was the best. The 28 d compressive strength of aeolian sand concrete replaced by 40% fly ash which was activated by 5% NaOH was equivalent to that of ordinary 20% fly ash aeolian sand concrete, and its pore structure was better, so as to effectively improve the utilization rate of fly ash and reduce the amount of cement. Furthermore, a predictive model of compressive strength GM(1,2) was established based on the gray entropy correlation degree. The average relative errors between predicted values and test values were 1.96% and 1.34%, with high accuracy.

关 键 词：风积沙混凝土 碱激发 抗压强度 孔结构 灰熵关联度 

分 类 号：TU528[建筑科学—建筑技术科学]