A railroad sleeper (1) for fixation of at least a pair of rails (2,2) of a railroad network is provided, including a contact surface (3), wherein each rail of the pair of rails (2,2) is fixed spaced apart from each other, the railroad sleeper (1) being configured by including a hollow sector (4) delimited by association of the contact surface (3) with the anchorage walls (5,5), thus establishing a free portion (17) adjacent to the anchorage walls (5,5) and opposite the contact surface (3). An embodiment in which the hollow sector (4) of the railroad sleeper is delimited by a support surface and the process of manufacturing a railroad sleeper is also provided.

A railroad sleeper (1) for fixation of at least a pair of rails (2,2) of a railroad network is provided, including a contact surface (3), wherein each rail of the pair of rails (2,2) is fixed spaced apart from each other, the railroad sleeper (1) being configured by including a hollow sector (4) delimited by association of the contact surface (3) with the anchorage walls (5,5), thus establishing a free portion (17) adjacent to the anchorage walls (5,5) and opposite the contact surface (3). An embodiment in which the hollow sector (4) of the railroad sleeper is delimited by a support surface and the process of manufacturing a railroad sleeper is also provided.

An extruded PVC railroad tie with glass fiber reinforcement contains glass fibers and clumps of pelletized glass fibers that enhance friction of all surfaces that are not coated with a cap stock. Parallel spaced apart interior walls enhance structural integrity. Two interior walls provide structures for threaded channels to threadedly and frictionally engage bolts for securing rail connection hardware. Interior compartments provide empty space for air and ballast. Air in the compartments moderates thermal expansion. A protective cap stock covers one or more sides, such as the exterior top and side surfaces of the tie. The bottom surface, which may be substantially devoid of a cap stock, exhibits roughness to grip and frictionally engage underlying ballast.

An extruded PVC railroad tie with glass fiber reinforcement contains glass fibers and clumps of pelletized glass fibers that enhance friction of all surfaces that are not coated with a cap stock. Parallel spaced apart interior walls enhance structural integrity. Two interior walls provide structures for threaded channels to threadedly and frictionally engage bolts for securing rail connection hardware. Interior compartments provide empty space for air and ballast. Air in the compartments moderates thermal expansion. A protective cap stock covers one or more sides, such as the exterior top and side surfaces of the tie. The bottom surface, which may be substantially devoid of a cap stock, exhibits roughness to grip and frictionally engage underlying ballast.

Natural fiber composite construction materials including boards, siding, railroad ties, standing seam roofing panels, roofing panels that support solar-electric modules, and roofing panels that support vegetation are provided. In various embodiments, composite construction materials comprise about 50-60% kenaf fiber.

Natural fiber composite construction materials including boards, siding, railroad ties, standing seam roofing panels, roofing panels that support solar-electric modules, and roofing panels that support vegetation are provided. In various embodiments, composite construction materials comprise about 50-60% kenaf fiber.