Some bond problems are obvious when an installation is performed over an unsuitable or questionable substrate, or over concrete that has been treated with curing compounds. Form-release compounds used in lift slab construction will also create bond problems. Shot blasting is generally accepted as the best method of removing these compounds.
Testing for the presence of these problem-causing substances - as well as for contaminants such as oil, etc. - is quick and simple. All you need do is thoroughly sweep clean the suspect area of the slab and drip beads of water on its surface. If the beads are not absorbed by the concrete within a few minutes, a potential bonding problem is indicated.