摘要
通过正交试验对不同配比的铁尾矿蒸压混凝土的强度进行极差分析,在得到较优配比的前提下,通过改变石灰掺量研究石灰掺量对铁尾矿蒸压混凝土的力学性能和抗冻性能的影响.实验结果表明:蒸养条件提高了铁尾矿的活性;在蒸养条件下,石灰掺量对铁尾矿蒸压混凝土的抗压强度有显著影响,随着石灰掺量的增加,其强度先升高后降低,石灰掺量为60%时取得最高强度值;石灰掺量对铁尾矿蒸压混凝土的抗冻性也有显著影响,随着石灰掺量的增加,其质量损失、强度损失均先升高后降低,60%石灰掺量试样的抗冻性最差,50%石灰掺量试样的抗冻性最好;在蒸养条件下,不同石灰掺量铁尾矿蒸压混凝土的主要水化产物为托勃莫来石、C-S-H和硬硅钙石,但含量和结晶程度差异较大;50%石灰掺量试样中存在结晶程度较好的托勃莫来石适量的穿插在C-S-H的网络结构中,试样抗冻性最好.
The range analysis of the strength of autoclaved concrete was carried on after the orthogonal experiment, and the optimum ratio was obtained. Then the mechanical properties and frost resistance of autoclaved concrete were studied with different lime contents. The experimental results show that the condition of steam curing improves the activity of iron ore tailings; under steam curing, lime content has a significant influence on the compressive strength of the autoclaved concrete prepared with iron tailings, with the increase of lime content, their strength decreases after the first increases, and the sample of 60% lime content gets the highest strength; lime content also has a significant influence on the frost resistance of the autoclaved concrete prepared with iron tailings, the mass and strength loss of concrete decreases after the first increases with the increase of lime content, and the sample with 60% lime content shows the worst frost resistance, but it has the best frost resistance with 50% lime content; In steam curing condition, the main hydration products of iron tailings autoclaved concrete with different lime contents are tobermorite, C-S-H and xonotlite, but their contents and the degrees of crystalline are different. The tobermorite with better degree of crystallization interspersed in the network structure of C-S-H appropriately in the sample of 50% lime content, and the sample obtained the best frost resistance.
出处
《武汉工程大学学报》
CAS
2016年第6期571-576,共6页
Journal of Wuhan Institute of Technology
基金
国家高技术研究发展计划(863计划)(SS2012AA062405)
国家自然科学基金(51078241)
关键词
蒸养
铁尾矿
石灰掺量
力学性能
抗冻性能
混凝土
autoclaved curing
iron ore tailings
lime content
mechanical property
frost resistance
concrete