Composite modifier and ultralow strength and high cohesiveness concrete prepared therefrom

The invention discloses a composite modifier, which comprises the following raw materials by mass: 15-25 parts of a polyester superplasticizer, 8-13 parts of a polyether water reducing agent, 7-12 parts of sodium thiosulfate, and 0.03-0.08 part of hydroxypropyl methyl cellulose. An ultralow strength and high cohesiveness concrete prepared from the composite modifier consists of the following components by mass: 250-350 parts of fly ash, 5-15 parts of the composite modifier, 150-250 parts of water, 800-950 parts of sand, and 850-1000 parts of stone. The concrete provided by the invention has the advantages of ultra-low strength, convenient breaking and removal in a later period, and short-term solidification. 本发明公开了种复合改性剂，以质量份数计，其原料包括：聚酯类高效减水剂15～25份、聚醚类减水剂8～13份、硫代硫酸钠7～12份、羟丙基甲基纤维素0.03～0.08份。种由上述复合改性剂制得的超低强度高粘聚性混凝土，所述超低强度高粘聚性混凝土是由以下质量份数的组分组成：粉煤灰250～350份、复合改性剂5～15份、水150～250份、砂子800～950份、石子850～1000份。本发明所述的混凝土既具有超低强度、方便后期破除的优点，又具有短期凝固的优点。