Problem Adding New Concrete Walls To Existing Concrete Walls Bonding

When using a liquid bonding agent paint the bonder onto the existing concrete and allow it to dry until it is tacky.

Problem adding new concrete walls to existing concrete walls bonding.

That would require major framing work since you would need a new sill around the house the old framed walls if that is in fact what you have would not line up with the new wall etc. Bonding fresh plastic concrete to old hardened concrete increases the strength of the composite material fresh patches concrete adjacent to construction joints and overlays all benefit from bonding to the hardened concrete substrate bond is not however guaranteed. Shin and wan 2010 investigated the interfacial bond strength of old and new concrete considering saturated surface dry ssd and air dry conditions. Fresh concrete can then be poured into the formwork and left to dry.

After 24 hours remove the formwork and allow the concrete wall to cure. The cement within a concrete mix doesn t contain any natural bonding agents so when fresh concrete is added on top of an existing layer of concrete the two won t join together. Existing concrete walls can be strengthened by retrofitting steel materials. This will not produce a strong serviceable floor.

Over time this expansion and contraction especially if they occur at different rates due to the sections of concrete being exposed to different temperatures will work the sections apart and the crack will widen. Then apply the repair material. Let s start by assuming you are concerned that the old wall is failing and you want to support the house on the new reinforced concrete wall. Saturated surface dry is a condition in which the concrete contains moisture that is equal to its potential absorption without the surface being wet or damp.

Quikrete concrete bonding adhesive no. Once cured the new concrete will simply sit on top as a separate layer. Exceeds the performance requirements of astm c 1059 type i and ii. This usually takes only a few minutes.

Eliminates the need for roughing the surface before the application. Just as in the process described above after the bonder has become tacky apply a scratch coat and then apply the repair material. 9902 permanently bonds new concrete plaster and stucco to existing concrete plaster and stucco. When joining new concrete work to old concrete work the joint will always develop a crack and will be a point of expansion and contraction.

This method does add a bit of weight to the walls but it can also be done with minimal disruption to anyone living or working inside the building. All damaged loosened or unbonded portions of existing concrete should be removed by chipping hammers or other mechanical methods.