Concrete Repair and Maintenance MCQ with answer and solution

Concept

Concrete Grouting Techniques

Formula

N/A

Step-by-step solution

1. Identify the maintenance procedure involving the injection of cement grout or chemicals into concrete cracks. 2. Recognize that filling voids and cracks using this method is defined as grouting. 3. Select Option C as the correct answer.

Explanation

Grouting is the process of filling cracks, gaps, or voids in concrete by injecting a liquid mixture of cement or special chemicals. Once this mixture hardens, it seals the cracks, prevents water from entering, and restores the strength and stability of the structure.

Shortcut

To easily remember the difference between Grouting and Pointing: - Grouting = Deep Injection: Injecting liquid grout under pressure into deep cracks, gaps, or voids in concrete. - Pointing = Surface Masonry: Finishing or filling exposed outer joints between bricks or stones with mortar. - Scouring = Riverbed Erosion: Washing away/erosion of soil around bridge piers by flowing water.

Common mistake

A common mistake is selecting option D (Pointing) by confusing it with grouting. Pointing refers to finishing or filling exposed joints in brick or stone masonry with mortar near the surface, whereas grouting specifically involves injecting a fluid mixture under pressure into deep cracks and voids in concrete. Another error is confusing scouring (option B), which is the physical erosion of riverbeds around bridge piers, with a repair method.