The invention discloses anti-
cracking concrete and a preparation method thereof, and the anti-
cracking concrete is prepared from the following raw materials in parts by weight: 400-450 parts of
cement, 600-700 parts of fine aggregate, 900-1000 parts of gravel, 70-80 parts of a composite additive, 30-40 parts of modified
fiber, 4-5 parts of a water
reducing agent and 160-180 parts of water, the composite additive is prepared from
fly ash, modified
sepiolite,
calcium sulphoaluminate and an air entraining agent; the modified
sepiolite is obtained by taking
sepiolite as a
raw material, pretreating the sepiolite through a
silane coupling agent and then sequentially reacting the pretreated sepiolite with
sulfanilamide and dodecyl
chloride. According to the invention, through the synergistic effect of the composite additive and the modified
fiber, the comprehensive improvement of the
crack resistance and
mechanical strength of the concrete is realized, in the composite additive, the moderate expansion of
calcium sulphoaluminate compensates the early shrinkage stress, the microbubble
system formed by the air entraining agent relieves the
stress concentration, and the dispersion effect of the polycarboxylate
superplasticizer is matched, so that the
crack resistance and
mechanical strength of the concrete are improved. The hardened body forms a compact and uniform
microstructure, and the tensile strength of the concrete is improved.