The use of fiberglass textile-reinforced mortar (TRM) jacketing system to enhance the load capacity and confinement of concrete columns

Abstract

Many buildings in the Middle-East are in need of rehabilitation mainly because of wars (such as in Iraq, Syria, and Yemen), or because of frequent earthquake events (like in Turkey, Iran, and Afghanistan). As such, there is a strong demand on developing the rehabilitation techniques that are effective from technical and economical point of views. In a textile-reinforced mortar (TRM) jacketing system, a high-strength textile is embedded into an inorganic matrix, and wrapped around the concrete member to provide the external reinforcement. This provides a cost effective renovation or rehabilitation technique that may be suitable for many developing countries. In general, columns are the most critical members of a building structure. Therefore, the focus of this thesis is on the retrofit of concrete columns with the TRM jacketing. The novelty of this research study is relevant to the way the TRM jacketing is carried out on an existing concrete column of square cross section. First, the TRM is wrapped around the column as a cylinder. Next, the mortar is applied on the external surface of the TRM jacket. Eventually, when the mortar is set, the inside of the TRM jacket is filled with a concrete grout to provide lateral confinement for the original column. Another component of this study includes investigating the influence of the type of mortar used on the load capacity and confinement of the concrete columns. The three mortar types include Ordinary mortar (OM), new mortar (NM), and 50% of the ordinary mortar mixed with 50% of the new mortar (50–50). Results of this experimental research study shows that the TRM jacket provides a significant increase in the compressive strength and ductility of the concrete columns. Application of the new mortar (NM) increases the compressive strength and confinement of the original columns by approximately 100%. Also, the 50–50 mortar as a more cost effective alternative, provides very good results by increasing the compressive strength by nearly 95%.