Composite fibers and methods of manufacturing composite fibers for the reinforcement of concrete are provided. The composite fibers include fibers and a polymeric coating. The composite fibers have a length of about 10 mm to about 80 mm and an equivalent diameter from about 0.3 mm to about 2 mm. A method for reinforcing concrete using the composite fibers is further provided.

Composite fibers and methods of manufacturing composite fibers for the reinforcement of concrete are provided. The composite fibers include fibers and a polymeric coating. The composite fibers have a length of about 10 mm to about 80 mm and an equivalent diameter from about 0.3 mm to about 2 mm. A method for reinforcing concrete using the composite fibers is further provided.

The invention relates to a method for producing artificial crushed sand by means of a thermal treatment using sand in the form of fine sand (FS/FSa) and/or round sand as the starting material (1). The starting material (1) in variant A is heated to a melting temperature by bundling sun rays (13), and/or the starting material in variant B is heated to a melting temperature by using a conventional melting device which achieves its energy supply using converted or stored solar power, whereby each of a plurality of sand grains are melted together into a three-dimensional intermediate product (2). The intermediate product (2) produced in this manner is cooled and finally comminuted to a particle size of less than 2 mm in a comminuting process. An end product (3) is produced which differs from the starting material (1) with respect to the shape and surface roughness. The method offers a long-term solution for meeting the demand for crushed sand and provides sand for the construction industry.

The invention relates to a method for producing artificial crushed sand by means of a thermal treatment using sand in the form of fine sand (FS/FSa) and/or round sand as the starting material (1). The starting material (1) in variant A is heated to a melting temperature by bundling sun rays (13), and/or the starting material in variant B is heated to a melting temperature by using a conventional melting device which achieves its energy supply using converted or stored solar power, whereby each of a plurality of sand grains are melted together into a three-dimensional intermediate product (2). The intermediate product (2) produced in this manner is cooled and finally comminuted to a particle size of less than 2 mm in a comminuting process. An end product (3) is produced which differs from the starting material (1) with respect to the shape and surface roughness. The method offers a long-term solution for meeting the demand for crushed sand and provides sand for the construction industry.