To reduce the cost of paint, fillers are added. If used too much it can weaken the paint. Alumina, magnesia, barite, charcoal, etc are examples of filler.
43.
Saponification is a defect on the painted surface and it is identified by the appearance of:
Emulsion paints have polystrene as a base. Emulsion paints are durable and can retain colour for too long. They dry within 15 minutes and hard dry within 2 hours.
46.
Which defect occurs if a paint is applied excessively thick?
If a paint is applied excessively thick then wrinkling occurs. Grinning occurs when under coat and final coat are of different colours. Running occurs if the surface is too smooth; paint run off from such parts. Flaking occurs due to poor adhesion, leading to peeling off of paint.
47.
In prestressed concrete structures the primary problem is damaged caused to ____________
The Damage caused to anchorages and unbounded tendons are the primary problems in prestressed concrete structures. Good maintenance includes periodical surveillance identification of local damage, deterioration and loss of durability of the structure due to environmental and other load effects.
48.
Rehabilitation of structures may be required due to several reasons. Choose the correct reason.
Environmental effects are one of the reason why rehabilitation of structures may be required. Other reasons may be constructional deficiency, deficiency in design, overloading of structures either due to unanticipated loading or due to accidents and user made changes in the structures during the service life of the structure.
The use of common techniques for rehabilitation of various structures is limited because the problem of rehabilitation is unique for the particular structure. Several new cementations materials and epoxy resigns and compounds have been developed which are highly effective in protecting the basic structure from the destructive effects of severe exposure conditions in the environment.
50.
Maintaining prestressed concrete structures of various types in a fit and serviceable condition is primary function of ____________
Maintenance engineer has the primary function of maintaining prestressed concrete structures of various types in a fit and serviceable condition. Investment towards effective periodical maintenance forms only a fraction of the cost to be incurred due to major repairs to rehabilitate the structures and hence it is always advisable to establish a programmed preventive maintenance system to detect any signs of distress in the initial stages itself through inspection procedures and appropriate repairs.
