脲酶诱导碳酸钙沉淀技术改良传统三合土的性能

Performance of Traditional Tabia Improved by Enzyme Induced Calcite Precipitation Technology

采用扫描电镜、X射线衍射等研究了脲酶诱导碳酸钙沉淀(EICP)技术对三合土性能的影响.结果表明:随着豆粉质量浓度的增大,脲酶活性呈近似线性增长,其最适宜的环境pH值为3~11,当环境pH值为12时,脲酶活性急剧下降;与三合土空白样相比,脲酶改性三合土14 d碳化深度提高了94%~112%,28 d抗压强度提高了68.0%~103.0%,耐候性提高了150%~200%,60 d表面硬度提高了15.0%~18.3%;三合土空白样产生的碳酸钙晶体松散,脲酶的掺入使三合土中出现了长条状晶体和团簇状晶体,且随着豆粉质量浓度的增大,团簇状晶体相对增多,长条状晶体相对减少,使三合土的各项性能逐渐提高.

The effect of enzyme induced calcite precipitation(EICP)technology on the properties of tabia was studied by means of scanning electron microscope and X‑ray diffractometry.The results show that urease activity increases approximately linearly with increasing of soybean powder mass concentration,and its optimum pH value is 3-11.When the pH value is 12,the activity drops sharply.Compared with the control sample of tabia,the carbonization speed of tabia modified with urease increases by 94%-112%in 14 days,the compressive strength increases by 68%-103%in 28 days,the weather resistance increases by 150%-200%,the surface hardness increases by 15.0%-18.3%in 60 days.The calcium carbonate crystals produced by the control sample of tabia are loose.After adding urease,long‑strip crystals and cluster‑like crystals appear in the tabia,and with the increase of soybean powder mass concentration,the cluster‑like crystals increase relatively,and the long‑strip crystals decrease relatively,the performance of tabia also gradually improves.