The present invention relates to a fiber board product comprising fibers in an amount from 50.0 to 99.0 parts by weight (d/d), at least one particulate calcium carbonate-containing material in an amount from 1.0 to 50.0 parts by weight (d/d), at least one binder in an amount from 0.05 to 25.0 parts by weight (d/d), at least one wax in an amount from 0 to 5.0 parts by weight (d/d), wherein the sum of the fibers and the at least one particulate calcium carbonate-containing material is 100.0 parts by weight (d/d), a process for manufacturing such a fiber board product as well as an use of at least one particulate calcium carbonate-containing material having a weight median particle size d.sub.50 of 0.5 to 150.0 m as fiber replacement in a fiber board product, preferably in a high-density fiber (HDF) board, medium-density fiber (MDF) board, low-density fiber (LDF) board or particle board.

A method of providing a reinforced bar (rebar) is disclosed for improved strength and flexibility for use in construction. The method includes forming a fiber reinforcement bar or strip such that it is flexible and coating its surface with a pozzolan to react to the cement. The rebar further includes a cross section to support bending moments and tensile loads. Various embodiments include modifications to the rebar shape such as strips, ribbons, and twisted forms for improved flexibility and mechanical interaction. Pozzolan constituents can vary, and a binding agent, possibly dicyclopentadiene, may be used for fiber binding. Further treatment such as rolling, compression, and addition of holes can enhance the surface area and ease of assembly, respectively. The method can also include processes such as chemically bonding steel through a transition layer to the reactive powder, melting of a glass frit to bind the reactive powder coating, or transferring pozzolans to an epoxy or plastic binder. The aim of these methods is to enhance the performance characteristics of the rebar and optimize its usefulness in various construction applications.

Concrete materials and thermal energy storage devices employing such concrete materials are disclosed herein. The concrete material may include fibers in an amount ranging from about 1 to about 2 vol. %; an aggregate in an amount ranging from about 50 to about 80 vol. %, wherein the aggregates comprises siliceous aggregate and optionally carbonate aggregate; and a cementitious material in an amount from about 12 to about 20 vol. %, wherein the cementitious material comprises a combination of about 70 to about 85 vol. % of Portland cement and about 15 to about vol. % of silica fume, wherein all volume percentages unless otherwise indicated are based on the total volume of the concrete material.