scholarly journals Utilization of Construction and Demolition Waste Along with Fly Ash waste in Preparing Non-Autoclaved Aerated Concrete

2020 ◽  
Vol 5 (3) ◽  
pp. 103-109
Author(s):  
Qunshan Wei ◽  
◽  
Kashif Ali Panhwar ◽  
Zuhair Nadeem ◽  
Kai Zhang ◽  
...  

China’s construction industries are rapidly increasing, and with that generation of Construction and Demolition waste is also growing, and another side industrial waste such as fly ash produced by a thermal power plant, Associated environmental issues, it is essential to utilize in any form; Studies by concrete experts have indicated the feasibility of suitably handling and recycling such waste in new concrete, mainly for basic-level applications. Non-autoclaved aerated concrete is a lightweight substance that could be used as substitute building materials; it is generally made up of raw materials such as Cement, quicklime, gypsum, sand, and expansion agent like an aluminum powder; in this study, 40% waste utilized, Construction and demolition waste (5%,10%,15%,20% ………40%) and Fly ash (35%,30%,25%,20%......0%) accordingly, while expansion agent maintained constant at 0.06%. The compressive strength of the final material checked after (7,14,21 and 28 days) respectively, obtained maximum strength after 28 days; this study goals to design a low cost, Non-autoclaved aerated concrete material and to reuse the waste produced from different sectors, mainly from the construction sector Keywords: Non-Autoclaved concrete, Lightweight concrete, Eco-friendly, Construction and Demolition waste, Fly ash

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.


2015 ◽  
Vol 244 ◽  
pp. 71-76 ◽  
Author(s):  
Alena Sicakova ◽  
Karol Urban ◽  
Martina Draganovska

Waste valorisation in production of building materials can be improved by their modification using some treatment technologies. Subsequently, products prepared using these optimized raw materials can show better or even new properties. Utilisation of construction and demolition waste (C&DW) for production of building materials is discussed for a longer time world-wide, whether in the form of coarse aggregates or in the fine-grain form as a micro-filler or as a binder. Both of these forms show specific problems have to be solved for increasing the quantities consumed. Fine-grain form can be obtained by techniques like crushing, grinding and sorting as well as by their combinations.This article is aimed on the utilization of specific portion of fine-grain C&DW (ceramics, glass and concrete) for production of concrete mixes of higher fluidity. C&DW were modified by specific process (defined method of crushing followed by sorting of particles under 250 μm). This material was expected as a micro-filler - substitution of natural aggregate (NA) in 0/4 fraction to the extent possible, that the rules allow. Using relevant calculations, 40% dosage was found as complying with standard limit for the maximum content (600 kg.m-3) of particles of less than 250 μm in whole mixture including the relative share of cement and NA. In accordance with these limiting factors, standard recipes were designed. Amount of water, as well as dosage of plasticizer was adjusted during mixing in order to keep the water/cement ratio (max. 0.6) and flow class F5 – F6.Resulting water consumption and dosage of plasticizer are discussed in the terms of influence of tested C&DW on the consistency and bleeding of concrete. Generally positive effect of fine-grain form of brick, glass and concrete was found compared to the reference concrete not containing those additive fine particles.


Author(s):  
Denitsa Hvarchilkova ◽  
Margarita Filipova ◽  
Ivanka Zheleva

For environment protection in the European Union (EU) it is very important the construction waste to be recycled and reused. The potential for the construction waste recycling and reuse is high, as their components have high cost. There is an opportunity for re-use of such materials in road construction, for drainage systems, for outdoor sports grounds and other construction sites. In 2012 a regulation on the management of construction waste and on the use of recycled building materials was adopted in Bulgaria, aiming to introduce a new model for the management of construction waste. This would guarantee: creation of favorable legislative and economic conditions for implementation of technologies ensuring the achievement of recycling and recovery targets but which are also financially viable in line with the country's incomes; identifying the persons responsible for covering the costs of building waste management and achieving the recycling and recovery targets; creating conditions for the production and marketing of materials from recycling of construction waste at a price that is competitive with the same new raw materials used in construction. The main effect expected from this normative document is to contribute to Bulgaria's development towards European trends, environmental protection through an integrated framework for the management of construction and demolition waste that will reduce the harmful impacts on it caused by construction waste, improving the efficiency of resource use, increasing the responsibilities of pollutants and stimulating investment in waste management.


2016 ◽  
Vol 249 ◽  
pp. 8-13
Author(s):  
Rudolf Hela ◽  
Martin Ťažký ◽  
Václav Vachuška ◽  
Tomáš Ťažký

Conventional high temperature fly ash has been used for manufacturing of construction materials, concrete in particular, for quite a long time. Fluidized bed combustion fly ash, however, has little use in this area, mainly for its chemical composition and morphology. Current efforts are directed towards the development of new technological processes and building materials that would allow the use of this industrial waste and its qualities. One possible way of fluidized bed combustion fly ash’s utilizing in construction industry is the production of cold balled lightweight aggregate. Production of this material is economically advantageous and enables processing of large volumes of raw materials. This paper describes possibilities of using this aggregate for production of lightweight concrete of lower compressive strength classes and consequent testing of durability and resistance to various types of aggressive environment and cyclical freezing and thawing. Physico-mechanical properties and microscopic defects were also studied


2018 ◽  
Vol 777 ◽  
pp. 518-522 ◽  
Author(s):  
Hoc Thang Nguyen ◽  
Thu Ha Bui ◽  
Vo Thi Ha Quyen Pham ◽  
Minch Quang Do ◽  
Minh Duc Hoang ◽  
...  

Fly ash is an industrial waste from coal-fired thermal power plants whereas red mud is an industrial waste generated during aluminum production from bauxite. If both fly ash and red mud are not properly managed, they could cause negative impact on the environment. This study utilized red mud and fly ash in combination with sodium silicate solution to produce a geopolymer-based material which can be used as building materials. This study focussed on the leachability of heavy metals in the raw materials and the geopolymer as this would be significant in assessing the environmental impact of the product. Leachability of heavy metals such as Cu, Zn, Cd, Pb, Fe, and Cr was evaluated based on European standard (EN 124572 – 2, EU CEN TC292/ CEN TC 308) with pH values at 7. The results showed that raw materials (red mud and fly ash) have higher leachability than geopolymer specimens. And the values of leaching tests for heavy metals in the geopolymer - based materials belonged to limits of EULFD and USEPA.


2020 ◽  
Vol 3 (2) ◽  
pp. 29-35 ◽  
Author(s):  
G. Medvedeva ◽  
A. Lifant'eva A.F.

the most important direction of resource saving in construction is the widespread use of secondary material resources, which are waste products. The use of secondary products of industry as raw materials for the production of various building materials is very important, because it provides production with rich sources of cheap and, often, already prepared raw materials; lead to lower costs for the production of some building materials, and therefore saves capital investments intended for the construction of buildings and structures; release large areas of land and reduce the impact on the environment. The article deals with heat-insulating and structural-heat-insulating materials, with partial replacement of components by ash-slag waste (ASW): lightweight concretes with broken glass and concretes modified with sulfur. Properties of concretes modified with sulfur are investigated: compressive strength, density and thermal conductivity. In accordance with the obtained properties, a comparative characteristics of the received materials with existing building materials was carried out: sulfur modified concrete and lightweight concrete; lightweight concrete using broken glass and claydite-concrete. Thermophysical calculation of multilayer hencing is made. In each of the options, one of the following materials was selected as a structural and heat-insulating material: lightweight concrete using broken glass and sulfur modified concrete. Also, for each type of hencing, the necessary heat-insulating and structural materials were selected. In the economic part, the cost of the raw materials necessary to obtain 1 m3 of the investigated materials and the cost of 1 m3 of multilayer hencing, which includes the investigated concrete, are calculated.


2017 ◽  
Vol 908 ◽  
pp. 106-110 ◽  
Author(s):  
Martin Ťažký ◽  
Lenka Bodnárová ◽  
Rudolf Hela

Increasingly we see today among the conventional high temperature fly ash also with the production of fly ash from fluidized bed combustion. These fluidized bed combustions fly ashes, however, have little used this area, mainly for their chemical composition and morphology. Current efforts are directed towards the development of new technological processes and building materials that would allow the use of this industrial waste and its qualities. One possible way of fluidized bed combustion fly ash’s utilizing in construction industries the production of cold balled lightweight aggregate. Production of this material is economically advantageous and enables processing of large volumes of raw materials. This paper describes possibilities of using this aggregate for production of lightweight construction concrete and consequent testing of durability and resistance to various types of aggressive environment. For these lightweight structural concretes, will be verified in their thermal-technical parameters.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2247
Author(s):  
Fernando da Silva Souza ◽  
José Maria Franco de Carvalho ◽  
Gabriela Grotti Silveira ◽  
Vitória Cordeiro Araújo ◽  
Ricardo André Fiorotti Peixoto

The lack of usable aggregates for civil construction in Rio Branco (capital of Acre, a Federal State in the Amazon region) makes the production and use of recycled aggregates from construction and demolition waste (CDW) an alternative of great interest. In this study, a comprehensive characterization of CDW collected from 24 construction sites of six building types and three different construction phases (structures, masonry, and finishing) was carried out. The fine and coarse recycled aggregates were produced and evaluated in 10 different compositions. The aggregates’ performance was evaluated in four mixtures designed for laying and coating mortars with a total replacement of conventional aggregates and a mixture designed for a C25 concrete with 50% and 100% replacement of conventional aggregates. CDW mortars showed lower densities and greater water retention, initial adhesion, and mechanical strength than conventional mortars. CDW concretes presented lower densities and greater resistance to chloride penetration than conventional concrete, with a small mechanical strength reduction. The recycled CDW aggregates proved to be technologically feasible for safe application in mortars and concrete; for this reason, it is believed that the alternative and proposed methodology is of great interest to the Amazonian construction industry, considering the high costs of raw materials and the need for defining and consolidating a sustainable development model for the Amazon region.


2021 ◽  
Vol 13 (14) ◽  
pp. 7572
Author(s):  
Gigliola D’Angelo ◽  
Marina Fumo ◽  
Mercedes del Rio Merino ◽  
Ilaria Capasso ◽  
Assunta Campanile ◽  
...  

Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of open porosity, water absorption, mechanical strength, and surface resistance values when compared to building materials produced using traditional technologies.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.


Sign in / Sign up

Export Citation Format

Share Document