1. Feasibility study on preparation of fully-waste building blocks using alkali-activated materials to solidify construction and demolition waste residue: Formulation optimization and reaction mechanism.
- Author
-
Wang, Zehui, Yuan, Quan, Zhou, Changdong, and Lu, Zhipeng
- Subjects
- *
CONSTRUCTION & demolition debris , *CALCIUM silicate hydrate , *WASTE recycling , *POZZOLANIC reaction , *RURAL development , *BRICKS , *FIRE resistant materials - Abstract
As a by-product of the construction and demolition waste (CDW) classification process, the construction and demolition waste residue (CDWR) faces the problem of having nowhere to be stacked and being unable to be handled. Solidifying CDWR by alkali activation technology to make building blocks not only provides a value-added method for recycling CDWR, but also promotes the sustainable development of rural construction. In this study, a new alkali-activated material (NAAM) was proposed for the solidification of CDWR, and the optimal ratio of NAAM at different curing ages was determined by mixture design, and then the micro-mechanism and macro-properties of CDWR solidified with NAAM were investigated. The results show that the compressive strength of the optimized specimen at 14-day meets the requirement of 10 MPa. After solidifying CDWR with NAAM, the products generated are mainly calcium silicate hydrate gels with different morphologies, accompanied by ettringite and CaCO 3. Water content and pH have a significant impact on the compressive strength, and low water content and pH value have a negative impact on the pozzolanic reaction and the generation of products of the specimen. In general, it is feasible to use NAAM mainly composed of waste brick powder proposed in this paper to solidify CDWR. Without using cement and natural aggregates, it still shows good mechanical property and environmental benefits. • A new alkali-activated material based on waste brick powder is proposed. • Recycling of construction and demolition waste residue as recycled aggregate. • The optimal ratio of NAAM at different curing ages is determined by mixture design. • The compressive strength of the optimized specimen at 14-day meets the requirement of 10 MPa. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF