The invention discloses a super-long super slow release type polycarboxylic acid
slump-retaining agent master batch suitable for projects such as hydraulic tunnels, railway tunnels, metros and underground oil and gas delivery adopting concrete having the capability of retaining
slump for 4-6 hours under the conditions of
hot weather and long distance. Limited by 40% of the
mass percent of mother liquid, the total
mass of synthesized raw materials is 1000 parts, the usage amount proportion is that the usage amount of polyether
macromonomer accounts for 325-335 parts, the usage amount of unsaturated
carboxylic acid micro-
monomer accounts for 10.0-18.0 parts, the usage amount of acrylic hydroxyalkanoate accounts for 35.0-45.0 parts, the usage amount of crosslinking
monomer accounts for 5.0-10.0 parts, the usage amount of
sulfonic acid type
chain transfer agent accounts for 2.0-5.0 parts, the usage amount of
hydrogen peroxide accounts for 2.0-3.5 parts, the usage amount of
vitamin C accounts for 0.60-0.90 part, the usage amount of caustic soda liquid accounts for 7-10 parts, and the balance is water. The polycarboxylic acid
slump-retaining agent is moderate in molecular weight, can be independently used or compounded with other polycarboxylic
acid water reducing agents for usage, can remarkably improve the indexes such as slump-retaining property, cohesiveness and flowing retention ability of newly mixed concrete in 6 hours.