The sensing involves two coplanar electrodes in the form of aluminum foil adhered to the cement-based material by using adhesive tape, which also serves as a dielectric film. The self-sensing of compressive and flexural stress in cement-based materials (without embedded or attached sensors, without admixture requirement and without poling) by capacitance measurement has been demonstrated. The experimental study reports the applicable grouting mortars and required material quality for the strengthening system. Adequate load-bearing capacity of the prestressing tendon anchorage was observed when some appropriate high-strength mortars were used. A pull-out test using PC tendon (defined in JIS G-3109) was conducted to examine the load-bearing capacity of the internal anchor. To examine the anchor effect, full-scale concrete members with wedge-shaped anchorage were prepared. The study focused on high strength mortar which is applicable in horizontal grouting and examined load-carrying capacity of the prestressing tendon embedded with the mortar. The purpose of this study is to extend the applicability of the developed strengthening system. Applications of the grouting mortar were difficult in some cases, such as horizontal grouting. The grout used in the previous study was a commercial pre-mixed high-strength mortar of 100 MPa. Note is that the anchoring effect in the system depends on the mechanical properties of grout material filled in the wedge-shaped hole. The wedge-shaped anchor achieved the load-bearing capacity up to the ultimate tensile force (448.7 kN) of PC tendon of a nominal diameter of 23 mm, which is defined in Japanese design code. A new strengthening system, which embeds a post-tensioned PC bar tendon into the wedge-shaped anchorage of an existing concrete member, has been developed in the previous studies.

Jis g 3109