A composite material comprises aggregate and an elastomeric composition. The elastomeric composition comprises the reaction product of an isocyanate component and an isocyanate-reactive component. The isocyanate component comprises a polymeric isocyanate, and optionally, an isocyanate-prepolymer. The isocyanate-reactive component comprises a hydrophobic polyol and a chain extender having at least two hydroxyl groups and a molecular weight of from about 62 to about 220. The chain extender is present in the isocyanate-reactive component in an amount of from about 1 to about 20 parts by weight based on 100 parts by weight of the isocyanate-reactive component. The aggregate may be rock, crumb rubber, and/or glass. The composite material has excellent physical properties and may be formed underwater, used in various locations, and used in various applications, such as for pavement, revetments, etc. Methods of forming and using the composite material and systems for forming the elastomeric composition are also disclosed.