CN-117602902-B - Concrete capable of being completely recycled, preparation method and recycling method thereof

Abstract

The invention discloses a concrete capable of complete circulation, a preparation method and a circulation method thereof, which fully and uniformly mix silicate cement, limestone coarse aggregate, river sand, limestone machine-made sand, copper slag, metakaolin and a water reducing agent, add water and stir uniformly, the fully recyclable concrete is obtained, after the service is finished, the fully recyclable concrete is crushed and calcined, and can be directly regenerated into high belite cement clinker for recycling, and the obtained cement clinker has good hardening performance and low calcining temperature.

Inventors

• LIU YUNPENG
• CUI YINGYING
• Xu Zongwang
• HU SHUGUANG
• CHOU JINENG

Assignees

• 武汉理工大学
• 湖南九华南方新材料科技有限公司

Dates

Publication Date

20260512

Application Date

20231122

Claims (1)

1. 1. The circulating method of the concrete capable of being completely circulated is characterized by comprising the following steps of fully and uniformly mixing silicate cement, limestone coarse aggregate, river sand, limestone machine-made sand, copper slag, metakaolin and a water reducing agent, adding water and uniformly stirring to obtain the concrete capable of being completely circulated, crushing the concrete after the service of the concrete capable of being completely circulated is finished and calcining the concrete at 1250-1300 ℃ to obtain high belite cement clinker, and adding 1-3% dihydrate gypsum of the clinker mass to obtain the high belite cement; The mass ratio of silicate cement to limestone coarse aggregate to river sand to limestone machine-made sand to copper slag to metakaolin to water is 1 (3.54-4.21): 1.14-1.20): 0.68-0.97): 0.47-0.72): 0.01-0.07: (0.68-0.80), and the obtained high belite cement clinker has a rate value of KH=0.67, SM= (1.83-2.28) and IM=0.64; The mass of the water reducer is 0.15-1.0% of that of the Portland cement; The copper slag contains 50-55% of Fe 2 O 3 by mass; The metakaolin contains 40-44% of Al 2 O 3 by mass.

Description

Concrete capable of being completely recycled, preparation method and recycling method thereof Technical Field The invention relates to the technical field of building materials, in particular to concrete capable of being completely recycled, a preparation method and a recycling method thereof. Background Cement concrete is a building material with the greatest dosage and the most wide application. Cement concrete not only consumes a large amount of high-quality sand resources, but also causes a problem of disposal and utilization due to the huge amount of cement concrete generated after the cement concrete is discarded. On the other hand, natural high-quality raw materials for cement production, such as calcium carbonate and the like, are increasingly lacking. The main oxide composition of the cement concrete is similar to cement clinker, and is CaO and SiO 2, so that the cement concrete has feasibility of replacing cement raw materials. And the hardened cement stone replaces calcium carbonate, so that CO 2 brought by calcium carbonate decomposition can be reduced. The existing technology for preparing regenerated cement by using waste concrete mainly uses coarse and fine or hardened cement stones which are crushed and separated by the waste concrete to replace cement raw materials, and also has the advantages that students replace all waste concrete by cement raw materials, more correction raw materials are still needed, and the hydration hardening performance of the regenerated cement clinker still has a certain gap compared with that of ordinary silicate cement. Chinese patent (application number 201010569489.6) discloses a method for preparing recyclable concrete, which uses the same raw materials as ordinary Portland cement clinker to prepare coarse and fine aggregates, then mixes cement, coarse and fine aggregates and water according to a certain proportion to prepare cement concrete, and then crushes, grinds and calcines the waste cement concrete at 1200-1450 ℃ to prepare cement clinker. However, the method needs to manually prepare coarse and fine aggregates, and the process is complex. Therefore, it is necessary to provide a recyclable concrete which can be directly used as a cement raw material after being discarded, and which can be used as a cement clinker again by high-temperature calcination, and which has a good hardening property. Disclosure of Invention In view of the above, the application provides a concrete capable of being completely recycled, a preparation method and application thereof, and the concrete can be directly regenerated into high belite cement clinker after being abandoned and recycled, and the obtained cement clinker has good hardening performance. In order to achieve the technical purpose, the application adopts the following technical scheme: the application provides a preparation method of completely recyclable concrete, which is characterized by comprising the following steps of fully and uniformly mixing silicate cement, limestone coarse aggregate, river sand, limestone machine-made sand, copper slag, metakaolin and a water reducing agent, adding water and uniformly stirring to obtain completely recyclable concrete, crushing, grinding and calcining after the service of the completely recyclable concrete is finished, and obtaining high belite cement clinker without correcting raw materials or a small amount of correction, wherein the recycled concrete is directly calcined to prepare recycled cement in the preparation process, namely taking waste into consideration, wherein river sand mainly provides SiO 2, copper slag mainly provides Fe 2O3, metakaolin mainly provides Al 2O3, limestone coarse aggregate and limestone machine-made sand mainly provide CaO, and the raw materials contain various impurity ions including Na +、K+、Mg2+、Al3+、Fe3+、P5+、S6+. Preferably, the step of curing the recyclable concrete is further included before crushing the recyclable concrete. After the curing of the recyclable concrete is finished, the recycled concrete is led into a jaw crusher to be crushed, then enters a ball mill to be ground, and is sieved by a square hole sieve with the size of 0.074mm until the sieve allowance is less than 10% of the material to be sieved, so as to obtain a recycled cement raw material, a small amount of correction raw material or no correction raw material is added into the recycled cement raw material, the recycled cement raw material is calcined after being uniformly mixed, and then quenched to obtain high belite cement clinker, and then gypsum is added to obtain the recycled concrete. Preferably, the mass ratio of silicate cement, limestone coarse aggregate, river sand, limestone machine-made sand, copper slag, metakaolin to water is 1 (2.82-4.21), 0.84-1.20, 0.59-0.97, 0.19-0.72, 0.01-0.07 and 0.54-0.80. Preferably, when the mass ratio of silicate cement, limestone coarse aggregate, river sand, limestone machine-made sand, copper slag, metakaolin and water