In the construction of concrete slabs that have a large enough area, often found cases of surface cracks. This type of crack also varies depending on the original cause. If the area is exposed to the sun’s heat after it is cast and added less curing, cracks on the surface due to rapid shrinkage are likely to occur. And for the repair of surface cracks due to this shrinkage, relatively easier and faster. Cracks caused by unexpected initial load contractions can be connoted as structural cracks. How big the luminosity and handling methodology is, depends on the initial investigation of the crack’s dimensions. Either concerning the depth, width, crack location and the approximate distribution of cracks within the slab body. A structural crack is found when a concrete surface inspection is performed before a waterproofing job is performed. Distribution of cracks occurs in the meeting point between the main beam / main girder and plate/slab concrete. The shape is elongated along with the location of the main girder, crack width varies with a minimum width of 2 mm and a depth ranging from 30 to 40 mm.
Initial investigation said the cracks occurred because of the decrease in the position of the slab in the middle of the landscape begins with scaffolding which decreases due to load from concrete and temporary loads such as workers and equipment. So there is an overdose and not time in joint main girder with the slab. And lead to the rift in the area. To find out the damage early, you can request our fix slab foundation service to check your concrete slab.
To ensure possible crack distribution in the slab concrete layer, an ultrasonographic examination is performed. The results of the examination showed that there were parts in the vacant slab (void) suspected to be related to this incident. After passing through various discussions and technical considerations, a handling method of low viscosity epoxy resin injection is selected in the slab. The work team chose Nitofill EPL / Conbextra EP 10 material to be injected into the concrete, while for the end cover/sealer used Nitomortar FC. There is no intention to promote the material mentioned above, but only on the basis of material performance considerations adjusted to field conditions and deadlines to be met. Further field observation was conducted for 1 week in a row and no new cracks were found in the repaired area. Ultrasonic grafi test is done again to make sure there is no void left. It should be borne in mind and emphasized that the use of compressors which provide the minimum pressure (20 bars) required at the time of injection is absolute. With such pressure, forcing epoxy resin material to run and meet the sidelines of cracks and voids in the concrete.