Stabilisation of construction and demolition waste with a high fines content using alkali activated fly ash

2018 ◽  
Vol 170 ◽  
pp. 26-39 ◽  
Author(s):  
Nuno Cristelo ◽  
Ana Fernández-Jiménez ◽  
Castorina Vieira ◽  
Tiago Miranda ◽  
Ángel Palomo
Keyword(s):  
Fly Ash ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Fines Content ◽  
Alkali Activated

scholarly journals Utilization of Construction and Demolition Waste, Fly Ash Waste in Autoclaved Aerated Concrete

2020 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Fly Ash ◽  
Aluminum Powder ◽  
Power Plants ◽  
Raw Materials ◽  
Thermal Power ◽  
Construction And Demolition Waste ◽  
Construction Sector ◽  
Demolition Waste ◽  
Concrete Material ◽  
Aerated Concrete

China's industries are rapidly growing, and with that generation of waste is also increasing. Associated environmental concerns over construction and demolition waste, industrial waste such as fly ash generated by thermal power plants need to be utilized in some form. Autoclave aerated concrete is a lightweight material that can be used as an alternative building material; it is widely composed of raw materials such as cement, quicklime, sand, gypsum, and an aerating agent like aluminum powder. In this study, 40% waste will be utilized, Construction waste (5%,10%,15%....40%) and Fly ash (35%,30%,25….0%)respectively, keeping the aerating agent constant at 0.06% that is aluminum powder. The compressive strength of the material will be checked after autoclaving at 2000 temperature and 1Mpa Pressure for 6 hours. The study aims to design an autoclave aerated concrete material and to recycle the waste generated by various industries mainly from the construction sector.

Construction and Demolition Waste (CDW) valorization in alkali activated bricks

2019 ◽  
pp. 495-499
Author(s):  
I. Lancellotti ◽  
V. Vezzali ◽  
L. Barbieri ◽  
C. Leonelli ◽  
A. Grillenzoni
Keyword(s):  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Alkali Activated

scholarly journals Acid Resistance of Lightweight Brick Powder Based Alkali Activated Material from Construction and Demolition Wastes

2018 ◽  
Author(s):  
Kai Tai Wan ◽  
Amende Sivanathan ◽  
Gediminas Kastiukas ◽  
Xiangming Zhou
Keyword(s):  
Acid Resistance ◽  
Strength Loss ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Construction And Demolition Wastes ◽  
Brick Powder ◽  
Structural Applications ◽  
The Matrix ◽  
Similar Density ◽  
Alkali Activated

The annual construction and demolition waste (CDW) generated from EU construction sector was 850 million tons, which represented 31% of the total waste generation and about 28% of CDW was ceramics (bricks and tiles). In this study, the feasibility of using CDW brick powder as the precursor of alkali activated mortar (AAM) and extruded polystyrene (XPS) as the lightweight aggregates to form lightweight brick powder AAM (LW-BP-AAM) for non-structural applications was investigated. The thermal conductivity of LP-BPAAM was 0.112 W/m·K with density of about 1,135 kg/m3 which was lower than the counterparts with similar density in literature. The acid resistance of LW-BP-AAM is comparable to conventional fly ash based AAM and superior than ordinary Portland cement. From the scanning electron microscopy with energy dispersive X-ray spectroscopy, there was no severe damage on the surface of LW-BP-AAM but aluminate was removed from the matrix which was further verified in Fourier transform infrared spectroscopy. The mass and strength loss of LP-BP-AAM was 1.5% and 33%, respectively. Although the compressive strength of the LP-BP-AAM was low (about 1.8 MPa), it can be improved by optimising the particle size of the XPS aggregates.

scholarly journals Construction and Demolition Waste as Recycled Aggregates in Alkali-Activated Concretes

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4016 ◽  
Author(s):  
Zahra Abdollahnejad ◽  
Mohammad Mastali ◽  
Mahroo Falah ◽  
Tero Luukkonen ◽  
Mehran Mazari ◽  
...  
Keyword(s):  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
High Calcium ◽  
High Calcium Concentration ◽  
One Step ◽  
Hardened State ◽  
Global Construction ◽  
Alkali Activated Concrete ◽  
Alkali Activated

The growth of global construction has contributed to an inevitable increase in the amount of construction and demolition (C&D) waste, and the recycling of C&D waste as aggregates in concrete is receiving increased interest, resulting in less demand for normal aggregates and bringing a potential solution for the landfilling of wastes. Recently, several studies have focused on the use of C&D waste in alkali-activated concrete to move one step closer to sustainable concretes. This paper focuses on the main mechanisms of using C&D waste in the resulting physical, mechanical, and durability properties of alkali-activated concrete in fresh and hardened state properties. The main difficulties observed with recycled aggregates (RA) in concrete, such as high levels of water demand, porous structure, and low mechanical strength, occur in RA alkali-activated concretes. These are associated with the highly porous nature and defects of RA. However, the high calcium concentration of RA affects the binder gel products, accelerates the hardening rate of the concrete, and reduces the flowability of alkali-activated concretes. For this reason, several techniques have been investigated for modifying the water content and workability of the fresh matrix and for treating RA and RA/alkali-activated binder interactions to produce more sustainable alkali-activated concretes.

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