Tensile Properties of Portland Cement Reinforced with Kevlar Fibers

Abstract

Composite specimens for tensile testing were made from various amounts of Kevlar fibers in Portland cement. Testing revealed about 50% improvement in the Elastic Modulus and yield strength over the unreinforced cement. The maximum amount of fibers, which was possible to add without destroying the continuity of the cement matrix, was about 2%. Specimens containing less than about 0.15% of fibers failed in a brittle manner like a single phase material. Specimens containing more than that amount of fibers displayed multiple fractures of the matrix before the final failure. The ultimate tensile strength started to improve at the critical volume of fibers equal to 0.3% and not as predicted theoretically at 0.75 % . The most dramatic improvement in the properties of cement was in the Energy to Fracture. This increased almost two orders of magnitude with 1.96% of fibers by volume.

Design of aromatic polyamides to modify cement performance under triaxial cyclic tests

“…The vesicular shape and size of the polymer imparts beneficial mechanical properties to cement through cement reinforcement, as well as, elasticity. [11,13,22] Polyamide reinforcement and strengthening are required because ordinary Portland cement lacks tensile strength to withstand extreme forces from any thermomechanical stress. In this study, reinforcement is provided by the embedment of polyaramid vesicles.…”

“…[7,8] Interest in cement-polymer composites and cements with embedded polymer powder/fibers have also contributed to some important chemical research and development. [6,[9][10][11][12] However, cementing in subterranean zones with higher temperature and pressures requires innovation in chemical additives to overcome cement integrity challenges.…”

“…The use of aramids, such as Kevlar fibers in cementing formulations is well documented in the literature and in patents. [11][12][13][14] In these applications, the fibers are taken and further prepared by either a downsizing process using alkaline hydrolysis to yield nanofibers or by grinding textile material into smaller particles. However, in this study, a number of crosslinked polyaramids are produced with varying flexible linkages, while maintaining all favorable polyaramid characteristics.…”

Mechanical properties of kevlar and jute fiber reinforced concrete

“…However, under high rate loading, the specimens prepared with fibers having 24 mm length exhibited higher strain energies than those prepared with 12 mm fibers. Konczalski and Piekarski [18] investigated the influence of Kevlar fibers on the tensile properties of ordinary Portland cement and found that using Kevlar significantly improves the elastic modulus and fracture energy.…”