Basalt Fiber Reinforced Polymer (BFRP) Materials for Reinforced Concrete Applications

Corrosion resistant carbon, aramid and glass fiber reinforced polymer (FRP) materials are currently used as internal or external reinforcement of concrete structural members. FRP materials are most useful in corrosive environment such as for marine structures, or bridge decks subjected to de-icing salts. However, these FRP materials are expensive for implementation in cost-critical projects. Basalt FRP made from fiber extracted from basalt rock might be a suitable cheaper alternative. Basalt fiber is known for its high temperature resistance, high strength, impact and blast resistance, and durability. FRP made with basalt fiber has these inherent properties.  Findings from several studies by the author over the last ten years on the suitability of basalt FRP are summarized for (i) external strengthening of existing concrete members (ii) internal reinforcement of concrete members, and (iii) fiber reinforced concrete (FRC) made from basalt FRP Minibar.  The behavior of reinforced concrete beams strengthened with BFRP and circular concrete compression members confined with BFRP was found to be comparable to the corresponding theoretical and experimental behavior of more established FRP systems. BFRP products are available for internal reinforcement of concrete in a variety of forms such as, straight rods, loops, two-dimensional mesh, and spirals. Flexural strengths, deflection, crack pattern, and the failure modes of the test specimens internally reinforced with BFRP bars were found to be satisfactory and consistent with BFRP material properties.  Use of small diameter BFRP bars known as Minibar was investigated for fiber reinforced concrete applications.  Minibar can be used at volumes of 2 to 10% to improve flexural tensile strength, post-cracking average residual strength and flexural fracture toughness.  Ballistic, containment, or protective structures and earthquake resistant structures are suitable applications for Minibar reinforced concrete.