▎ 摘　　要

NOVELTY - Concrete slump retaining agent, comprises 1.5-3 pts. wt. graphene oxide, 15-18 pts. wt. 2-chloroacrylic acid, 18-21 pts. wt. solid base, 330-460 pts. wt. methallyl polyoxyethylene ether or isopentenyl polyoxyethylene ether, 1.8-6.4 pts. wt. initiator, 3-6 pts. wt. chain transfer agent, 0.4-1.4 pts. wt. reducing agent, 6-22 pts. wt. alkenoic acid compound, 23-46 pts. wt. acrylate compounds and 400-500 pts. wt. water. USE - Used as concrete slump retaining agent. ADVANTAGE - The slump retaining agent: can be stably adsorbed on the surface of cement particles, delay hydration reaction; reduces the loss of concrete over time; and improves the dispersion performance through the template effect of carboxylated graphene and thus improving the dispersibility of the slump retaining agent to the slurry system and enhancing the slump retaining effect of concrete. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) Preparing concrete slump retaining agent comprising (i) evenly mixing graphene oxide and water, adding solid base to react with 2-chloroacrylic acid to prepare carboxylated graphene dispersion, (ii) adding methallyl polyoxyethylene ether or isopentenyl polyoxyethylene ether into the carboxylated graphene dispersion to mix uniformly, and then adding initiator to mix uniformly, and (iii) respectively preparing aqueous solution 1 mixed with chain transfer agent and a reducing agent, and an aqueous solution 2 mixed with alkenoic acid compound and acrylate compound, adding aqueous solution 1 and aqueous solution 2 simultaneously into the mixed solution obtained in step (ii) below 45degreesC, where the dropwise addition time of aqueous solution 1 and aqueous solution 2 is 2-3.5 hours, reacting for 1-2 hours after the dripping, and adjusting the pH to 6.8-7.2 with a pH regulator; and (2) Concrete material, comprising the concrete slump retaining agent.