非发泡高聚物预应力锚杆模型试验研究

Model Test Study on Non-Foamed Polymer Prestressed Anchor

为研究非发泡高聚物注浆材料应用于预应力锚杆支护中的可行性,采用室内试验的方法研究了锚固体系两界面间的黏结特性,并对影响因素进行了分析.在室内试验的基础上采用大比例尺模型试验,对非发泡高聚物预应力锚杆进行了试验研究.结果表明:当基体强度不大于30 MPa时,非发泡高聚物与混凝土基体间的黏结强度随着基体强度的增大而增加,高聚物与螺纹钢筋间的黏结强度随着钢筋直径的增大,平均黏结强度先增大后减小;高聚物锚固体在荷载作用下具有一定的柔性,卸载后有回弹;锚杆张拉锁定后,预应力损失主要集中在前24 h,随着锚固深度的增加,预应力损失逐渐较小.

In order to study the feasibility of non-foamed polymer grouting material used in prestressed bolt support,the method of laboratory test was used to study the bonding characteristics between the two interfaces of the anchor system,and its influence factors were analyzed.On the basis of the indoor test,a large-scale model test was used to test the non-foamed polymer prestressed bolt.The test results showed that when the matrix strength was not greater than30 MPa,the bond strength between the non-foamed polymer and the concrete matrix increased with the increase of the matrix strength,and the bond strength between the polymer and the rebar increased with the diameter of the steel bar,the average bond strength first increased and then decreased.Polymer anchors had certain flexibility under load,and rebound after unloading.After the anchor rod was tensioned and locked,the prestress loss was mainly concentrated in the first 24 hours.As the anchoring depth increased,the prestress loss was gradually smaller.