Title: Effect of Curing and Addition of Polypropylene Fibers on Selected Properties of High-Strength Concrete

Author(s): Saud F. Al-Otaibi and Waheeb Al-Khaja

Publication: Symposium Paper

Volume: 172

Issue:

Appears on pages(s): 351-374

Keywords: Compressive strength; curing; drying shrinkage; high-strength concretes; plastics, polymers and resins; polypropylene fibers; silica fume; tensile strength

DOI: 10.14359/6141

Date: 12/1/1999

Abstract:
The harsh environmental conditions in the Arabian Gulf region calls for the use of high performance concrete and utilizing the recent developments in concrete technology in terms of materials and practices to produce concrete with high quality. This paper presents results of an investigation to evaluate the effect of curing and the addition of polypropylene fibers on the properties of high strength concrete. In this study, four high strength mixes with compressive strengths in the range of 65 to 80 MPa were made and tested. The first was a plain mix with a cementitious content of 450 kg/m3, the second was a plain mix with polypropyplene fibers, the third was a silica-fume blended mix (10% cement replacement), and the fourth was a silica-fume mix with polypropylene fibers. These specimens were subjected to three curing conditions: moist curing, dry curing and use of curing compound. The specimens were tested for compressive strength, tensile strength, drying shrinkage and plastic shrinkage cracking. The results clearly show the importance of curing on the quality of concrete. The use of silica fume contributes to the increase of concrete strength and reduction of drying shrinkage. The results also show the contribution of polypropylene fibers in reducing plastic shrinkage cracking and the need for early curing to prevent plastic shrinkage cracking in fresh concrete.