The invention belongs to the field of building materials, and in particular relates to elastic concrete used for rapidly repairing an expansion joint. The elastic concrete is composed of three groups of materials, namely a material A, a material B and a material AC, wherein the weight ratio of the material A to the material B, to the material C is 1: (1-2.5): (8-18), the material A is composed of isocyanate or a prepolymer of the isocyanate, the material B is composed of the following components in parts by weight: 100-105 parts of polyhydric alcohols, 4-30 parts of a plasticizer, 5-20 parts of a chain extender, 0.01-1 part of a catalyst, 20-100 parts of a filler, 0-3 parts of an antioxidant, 0-3 parts of a defoamer, 0-30 parts of a coupling agent and 0-20 parts of a pigment, and the material C is aggregate. The elastic concrete has the advantages of high curing speed, adjustable curing time, good application property and self-leveling property. The elastic concrete is environment-friendly, good in toughness and small in contraction, has no generation of secondary cracking during operation process, good caking property with a base surface and excellent durability.