دانلود کتاب FIB 41: Treatment of imperfections in precast structural elements

fib Bulletin 41 addresses the most common types of imperfections encountered during the manufacture, stacking, transport and erection of precast concrete structural elements, and suggests a number of possible remedial actions. The remedial actions depend on the severity of the imperfection, the feasibility of repair and the consequences on the intended use of the concrete member.Imperfections in concrete structures are impossible to avoid and can range from minor surface blemishes to major structural defects. Because many imperfections are at the limits of specified quality deviations, or are not included in the acceptance criteria, the problem is more complex than a decision between rejection or acceptance.This document deals with precast concrete elements that do not meet the quality as intended in the design. It compares imperfections in quality to the specified requirements so that the effect of the imperfection can be evaluated. Recommendations are provided on methods to prevent such imperfections, the effect they can have and any necessary actions for rectification.The bulletin applies to prefabricated concrete members made of reinforced or prestressed normal weight concrete. Products include beams and columns, concrete walls, hollow core slabs, double tees, planks and beams for beam and block floors. Water retaining structures are outside the scope of this document.