Title: Design Predictions of Crack Widths in Ferrocement

Author(s): Antoine E. Naaman

Publication: Symposium Paper

Volume: 61

Issue:

Appears on pages(s): 25-42

Keywords: cracking (fracturing); crack width and spacing; ferrocement; flexural strength; serviceability; structural design; tensile stress; tension tests; wire cloth.

DOI: 10.14359/6634

Date: 8/1/1979

Abstract:
One of the distinguishing features of ferrocement as compared to reinforced concrete is the larger number of finer cracks for the same stresses in the steel reinforcement. Designing ferrocement structures to satisfy recommended serviceability criteria in a manner similar to the design of reinforced concrete structures is a logical and rational approach to follow. Serviceability is greatly dependent on cracking and crack width under working load conditions. Thus the prediction of crack widths (average and/or maximum) is an important consideration in design. This paper is based on a number of recent investigations on the cracking of ferrocement elements: they include tests on flexural beams under static and fatigue loadings, tests on ferrocement prisms with and without transverse reinforcement subjected to direct tensile loads, and tests on internally pressurized model ferrocement cylindrical water tanks. The following aspects of cracking are clarified for both flexure and tension: cracking behavior; influencing parameters; observed variations of crack widths; crack width predictions and suggested design approach.