The materials used to create pavers are simple: Sharp sand, Small stone chips, Cement powder, Water, and Pigment. According to Unilock Materials, Specialized machinery is used to mold and press these pavers. These concrete pavers are two to three times stronger than regular poured-in-place concrete. The fact that they are so strong, offers a Lifetime Warranty. An advantage in terms of design is that the manufacturing process allows the creation of paving stones and retaining wall blocks in different colors, shapes and textures.