This manuscript presents a method for controlling the quality of installation for spike anchors designed to delay delamination of externally bonded fiber reinforced polymers. The protocol includes the preparation of the drill hole and the insertion process. The most influential parameters on the efficiency of the anchors are discussed.
The overall goal of this procedure is to optimize the installation quality for fiber reinforced polymer spike anchors and to procure the maximum reproducibility for the anchors installation. This method can help answer questions in the field of concrete enforcement with fiber reinforced polymers. Such as, how anchors contribute to the and what parameter affect the anchor performance.
The main advantage of this technique is that it guarantees proper quality of installation, thus reducing uncertainties about whether the fibers are kinked. Demonstrating this procedure will be Sergio Gonzalez and Romeo Sabou. Two technicians who help in our laboratory research.
Prepare a masonry or concrete structure for drilling a hole. In this case, it is concrete with a compressive strength of 30 megapascals. For an anchor, use 10 millimeter fiber rope.
Its diameter will expand from 10 up to about 14 millimeters when impregnated. Use a rotary hammer to begin drilling a 20 millimeter diameter hole to allow for a six millimeter clearance. Occasionally, interrupt drilling the hole to insert a rigid bar of known length into the drilling hole.
Measure the length that remains exposed and determine the embedded length. Continue on to smoothing the hole when the length is acceptable. Smoothing the hole out is crucial to the many sinking of fibers and also to conquer the quality of installation.
For this procedure, a specific drill bit was assigned. For first dust removal, use a blow out hand pump and blow the hole out, at least twice. When done, prepare to smooth the hole with a non-percussive rotary tool.
This one is equipped with a customized drill bit that can be easily adapted to other equipment. Arrange for water to continuously cool the substraight. Then, begin smoothing the hole with the tool.
Stop when the drill bit touches the concrete surface. Ensure that the hole does not have any sharp edges before proceeding. Next, begin cleaning the hole with a blow out hand pump.
After blowing, set aside the pump and obtain a wire brush. Select the diameter to be as close to that of the hole as possible. Insert the brush, then rotate it around the brush's axis to have equal friction around the hole.
Once brushing is complete, always blow the hole out again. Perform the blow, brush, blow cycle at least twice before continuing. Before inserting the anchor, get the first ply of fiber reinforced polymer reinforcement.
Apply epoxy resin to the substraight using a roller or a brush. Then apply the fiber reinforced polymer reinforcement. Smooth out the poly reinforcement before continuing.
To expose the hole, split the longitudinal fibers of the reinforcement in two sections. To prepare an anchor, first cut the rope to the required length. The length must be equal to the sum of the embedded and anchor fan lengths.
In addition, have a cable tie ready. Next, work with a low viscosity epoxy primer and a soft brush. Hold the anchors bending region and begin impregnating the fibers with epoxy toward the end of the connector.
Partially fan out the anchor dowel to guarantee proper penetration of the resin. When done, immediately fasten the impregnated end with a cable tie. Then, use a long wire to pierce the cable tie.
Push the anchor dowel into the prepared hole. Now, apply the same epoxy resin used on the substraight reinforcement interface to the reinforcement and the anchor fan. Employ a bubble roller after each application of resin.
This is a scatter plot with the embeddment lengths on the horizontal axis and the tensile performance of an anchor normalized by its tinsel strength on the vertical axis. The data points are mean values and the arrow bars represent the central 95%of the distribution. Note, there is an almost linear increase of the anchor capacity within embedment length for both wet and procured installation methods.
Scatter is reduced with the wet method particularly for lengths between 75 and 100 millimeters. We first had the idea for this method when we observed how relevant installation parameters were over of previous research. Once mastered, this technique requires between five and 10 minutes of drilling, plus 15 minutes of cleaning and 15 minutes of incorporation and insertion.
While attempting this procedure, it is important to check that the total length of the fiber is enough for both embedded length and the anchor fan. Smoothing the hole out can be complimented with a range of dual angels greater than 90 degrees to prevent fiber kinking. The development of this product is a starting point on research of contribution of multiple anchors on bonded FRP.
After watching this video, you should have good understanding of how to prepare and install a piece by concrete. Please, don't forget that working with chemical agents such as epoxy resin, can be extremely hazardous and precautions must be taken such as the use of gloves and glasses.
