scholarly journals STRUCTURE FORMATION IN ALKALI ACTIVATED ALUMINOSILICATE BINDING SYSTEMS USING NATURAL RAW MATERIALS WITH DIFFERENT CRYSTALLINITY DEGREE

2020 ◽  
pp. 38-43 ◽  
Author(s):  
N. Kozhuhova ◽  
V. Strokova ◽  
M. Kozhuhova ◽  
Igor' Zhernovskiy
Keyword(s):  
Structure Formation ◽  
Raw Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Deep Understanding ◽  
Science Field ◽  
Crystallinity Degree ◽  
Classic Problem ◽  
Alkali Activated Binders ◽  
Alkali Activated

the efficiency of traditional raw materials using as well as expanding of potential uses for non-conventional and alternative raw materials with different origin is the tasks exiting interest among material scientists and manufacture stuff. Investigation of the above is oriented on solution of such scientific problem as more deep understanding of structure and features of material. The results obtained also allow solution of some technological, technical and economical tasks. Greatly, it is actual when using of new types of raw materials as well as when synthesis of new composites. Concerning the construction material science field, the classic problem is the looking for ways to study the reactivity of raw components under different conditions, its control and, generally, its increasing to produce higher performance materials. Among the popular and widely-used construction materials are alkali-activated binders and relevant composites. In this study the results of granulometric analysis of suspension based on alkali-activated aluminosilicate with different crystallinity degree are presented. It was found, when treatment of aluminosilicate grain by alkali activator leads to the grain solubilizing (but differently depending on crystallinity degree of aluminosilicate) and formation of alkali-aluminosilicate gel that reacts with unreacted part of the grain according to structure affinity principle. It was also determined the crystallinity degree of aluminosilicate component is inversely proportional to its solubility in highly-alkali environment. The model of structure formation for geopolymer system under alkali effect is offered.

Reuse of Municipal Wastewater Sludge for Construction Material

2010 ◽  
Vol 156-157 ◽  
pp. 939-942 ◽  
Author(s):  
Deng Ling Jiang ◽  
Guo Wei Ni ◽  
Guan Yi Ma
Keyword(s):  
Municipal Wastewater ◽  
Raw Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Matter Content ◽  
Wastewater Sludge ◽  
Dry Matter Content ◽  
Sludge Disposal ◽  
Paper Wastewater ◽  
Feasible Alternative

Treatment of municipal wastewater results worldwide in the production of large amounts of sewage sludge. The major part of the dry matter content of this sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary (microbiological) sludge. The sludge also contains a substantial amount of inorganic material and a small amount of toxic components. The large volume of wastewater sludge generated requires enormous landfill space for disposal. Diverting the wastewater sludge from landfill would alleviate the shortage of landfill sites. Thus alternative applications have to be considered for the wastewater sludge diverted away from the landfills. The use of wastewater sludge for the production of construction materials is reviewed in this paper. Wastewater sludge can be used as raw materials for making bricks, concrete filler and concrete aggregates. The study reveals that the reuse of wastewater sludge as construction materials offers a technically feasible alternative for sludge disposal.

scholarly journals Radiological and physico-chemical characterization of red mud as an Al-containing precursor in inorganic binders for the building industry

2021 ◽  
Vol 36 (2) ◽  
pp. 182-191
Author(s):  
Ljiljana Kljajevic ◽  
Miljana Mirkovic ◽  
Sabina Dolenec ◽  
Katarina Ster ◽  
Mustafa Hadzalic ◽  
...  
Keyword(s):  
Construction Industry ◽  
Natural Radioactivity ◽  
Red Mud ◽  
Building Materials ◽  
Raw Materials ◽  
Construction Materials ◽  
Polymerization Process ◽  
Alkali Activation ◽  
Silica Alumina ◽  
Alkali Activated

The potential re-use of red mud in the building and construction industry has been the subject of research of many scientists. The presented research is a contribution to the potential solution of this environmental issue through the synthesis of potential construction materials based on red mud. A promising way of recycling these secondary raw materials is the synthesis of alkali-activated binders or alkali activated materials. Alkali-activated materials or inorganic binders based on red mud are a new class of materials obtained by activation of inorganic precursors mainly constituted by silica, alumina and low content of calcium oxide. Since red mud contains radioactive elements like 226Ra and 232Th, this may be a problem for its further utilization. The content of naturally occurring radionuclides in manufactured material products with potential application in the building and construction industry is important from the standpoint of radiation protection. Gamma radiation of the primordial radionuclides, 40K and members of the uranium and thorium series, increases the external gamma dose rate. However, more and more precedence is being given to limiting the radiological dose originating from building materials on the population these days. The aim of this research was to investigate the possible influence of alkali activation-polymerization processes on the natural radioactivity of alkali activated materials synthesized by red mud (BOKSIT a. d. Milici, Zvornik, Bosnia and Herzegovina) and their structural properties. This research confirmed that during the polymerization process the natural radioactivity was reduced, and that the process of alkali activation of raw materials has an influence on natural radioactivity of synthesized materials.

Alkali Activated Binders Based on Metakaolin

2015 ◽  
Vol 1 ◽  
pp. 200
Author(s):  
Laura Sele ◽  
Diana Bajare ◽  
Girts Bumanis ◽  
Laura Dembovska
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Raw Materials ◽  
Sodium Silicate Solution ◽  
Total Porosity ◽  
Lead Silicate ◽  
Cement Production ◽  
Alkali Activated Binders ◽  
Alkali Activated

<p>According to research conducted in last 25 years, alkali activated binders have been considered as one of the most progressive alternative binders, which can effectively replace Portland cement. Production of alkali activated binders differs from the Portland cement production and is associated with lower CO2 emissions. The use of recycled industrial by-products and wastes is also possible, what corresponds to the future guidelines and principles of sustainable binder production in the world.<br />The aim of this study was to create innovative alkali activated binders by using secondary raw materials, which will be different from the ones described in the scientific literature – alkali activated binders with porous structure. Raw materials used for the binders were metakaolin containing waste, waste from aluminium scrap recycling factory and recycled lead-silicate glass; solid contents were activated with modified sodium silicate solution with an addition of sodium hydroxide.<br />The physical properties of alkali activated binders, such as density, water absorption, open and total porosity, were determined and flexural and compressive strength of hardened alkali-activated binders were tested at the age of 28 days. Durability was examined by sulphate resistance test, which was performed according to SIA 262/1, appendix D: applicability and relevance for use in practice. 40x40x160 mm prismatic specimens were used for expansion measurement and determination of compressive strength. <br />The open porosity of obtained materials was up to 45%, density from 380 to 1720 kg/m3, compressive strength up to 29,8 MPa, water absorption 6 – 114 wt.%. After analysing the results from the sulphate test it was concluded that glass additive reduced the alkali activated binder resistance to sulphate attack.</p>

scholarly journals Sulfate-bearing clay and Pietra Serena sludge: Raw materials for the development of alkali activated binders

2021 ◽  
Vol 301 ◽  
pp. 124030
Author(s):  
Roberta Occhipinti ◽  
Ana M. Fernández-Jiménez ◽  
Angel Palomo ◽  
Serena C. Tarantino ◽  
Michele Zema
Keyword(s):  
Raw Materials ◽  
Alkali Activated Binders ◽  
Alkali Activated

Properties of Self-Compacting Geopolymer Concrete

2014 ◽  
Vol 803 ◽  
pp. 99-109 ◽  
Author(s):  
Muhd Fadhil Nuruddin ◽  
Fareed Ahmed Memon
Keyword(s):  
Construction Industry ◽  
Fossil Fuels ◽  
Negative Impact ◽  
Raw Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Cement Production ◽  
Cement Manufacture ◽  
The Moment ◽  
The Impact

Concrete has been used in the construction industry since long times. It is probably the most widely used construction material in the world, largely due to the abundance of the raw materials for cement manufacture, low relative cost and the versatility and adaptability of concrete in forming various structural shapes. Massive production of concrete and the associated substantial manufacture of cement have however been observed to have a very negative impact. One of the biggest issues of growing concern at the moment faced by concrete industries is the impact of cement production on the environment. The production of cement not only depletes significant amount of natural resources, but also liberates a considerable amount of carbon dioxide (CO2) and other greenhouse gases into the atmosphere as a result of decarbonation of limestone and the combustion of fossil fuels. In addition, cement is among the most energy intensive construction materials, after aluminium and steel [1].

scholarly journals Iron and Aluminium Production Wastes as Exclusive Components of Alkali Activated Binders—Towards a Sustainable Alternative

2021 ◽  
Vol 13 (17) ◽  
pp. 9938
Author(s):  
Nuno Cristelo ◽  
Fernando Castro ◽  
Tiago Miranda ◽  
Zahra Abdollahnejad ◽  
Ana Fernández-Jiménez
Keyword(s):  
Co2 Emissions ◽  
Building Materials ◽  
Negative Impact ◽  
Raw Materials ◽  
Construction Materials ◽  
Heat Of Hydration ◽  
Sustainable Construction ◽  
Alkaline Solutions ◽  
By Products ◽  
Alkali Activated

The sustainability of resources is becoming a worldwide concern, including construction and building materials, especially with the alarming increase rate in global population. Alternative solutions to ordinary Portland cement (OPC) as a concrete binder are being studied, namely the so-called alkali-activated cements (AAC). These are less harmful to the environment, as lower CO2 emissions are associated with their fabrication, and their mechanical properties can be similar to those of the OPC. The aim of developing alkali-activated materials (AAM) is the maximization of the incorporated recycled materials, which minimises the CO2 emissions and cost, while also achieving acceptable properties for construction applications. Therefore, various efforts are being made to produce sustainable construction materials based on different sources and raw materials. Recently, significant attention has been raised from the by-products of the steelmaking industry, mostly due to their widespread availability. In this paper, ladle slag (LS) resulting from steelmaking operations was studied as the main precursor to produce AAC, combined with phosphating bath sludge—or phosphate sludge (PS)—and aluminium anodising sludge (AS), two by-products of the surface treatment of metals, in replacement rates of 10 and 20 wt.%. The precursors were activated by two different alkaline solutions: a combination of commercial sodium hydroxide and sodium silicate (COM), and a disposed solution from the cleaning of aluminium extrusion steel dies (CLE). This study assesses the influence of these by-products from the steelmaking industry (PS, AS and CLE) on the performance of the alkali-activated LS, and specifically on its fresh and hardened state properties, including rheology, heat of hydration, compressive strength and microstructure and mineralogy (X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy and Fourier transform infra-red. The results showed that the CLE had no negative impact on the strength of the AAM incorporating PS or/and AS, while increasing the strength of the LS alone by 2×. Additionally, regardless of the precursor combination, the use of a commercial activator (COM) led to more fluid pastes, compared with the CLE.

scholarly journals Experimental Research on Strength Properties of Concrete (M60) Partially Fine Aggregate Replaced with Waste Crushed Glass.

2019 ◽  
Vol 8 (4) ◽  
pp. 700-704
Keyword(s):  
Raw Materials ◽  
Construction Material ◽  
Concrete Strength ◽  
Research Work ◽  
Construction Materials ◽  
Strength Test ◽  
Fine Aggregate ◽  
Acid Attack ◽  
Chloride Permeability ◽  
Split Tensile Strength

Due to increased construction practices there was a very high demand in consumption of raw materials that are to be used in concrete. In the raw materials, sand is one of the major construction materials that is consumed adequately. It’s presence will be vanished due to excessive digging .The effect will be to the nearby localities .As well the stability hydraulic structures nearby river banks will be affected with this. To reduce digging practices the fine aggregate was partially replaced with waste crushed glass in 0%,10%,20%,30% andv40% along with 0.25%Super plasticizer SP 430 to achieve workability. The crushed glass is non-biodegradable and cannot be disposed off, also causes several environmental effects. By utilizing this waste as a useful material in the form as replacing material of fine aggregate we can reduce the waste content and in the same way it can be used as a resource. In order to check the concrete strength and durability tests like Compressive strength test, Split tensile strength test, Flexural strength test for 7,14,28 days curing and acid attack test, rapid chloride permeability test, Abrasion tests were conducted. SEM tests are also conducted on concrete with replaced fine aggregate. The current research work describes the proper utilization of waste crushed glass as a useful construction material.

Fundamentals of Geopolymers and Related Alkali Activated Materials

2014 ◽  
Vol 803 ◽  
pp. 144-147 ◽  
Author(s):  
J. Temuujin ◽  
A. Minjigmaa ◽  
U. Bayarzul ◽  
Ts. Zolzaya ◽  
B. Davaabal ◽  
...  
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Raw Materials ◽  
Construction Materials ◽  
Materials Chemistry ◽  
Low Carbon ◽  
Pond Ash ◽  
Sustainable Usage ◽  
By Products ◽  
Alkali Activated

With the increasing rate of depletion of natural raw materials for production of building materials, their sustainable usage is clearly an important topic for consideration. For instance, 1 tonne ordinary Portland cement (OPC) requires 1.7 tonnes of raw materials, 1.0 tonne of coal and 100 kWh of electricity. One tonne of cement emits 0.8 - 1 tonne of CO2 into atmosphere globally contributing ~5% of total manmade carbon dioxide. Therefore, the development of new, sustainable, low carbon footprint construction materials is an important task for materials scientists and civil engineers. One type of binder that is attracting particular attention around the world is alkali-aluminosilicate chemistry based material the so-called geopolymers. In this presentation we will discuss the fundamentals of geopolymer chemistry and the similarities to and differences from conventional alkali activated materials chemistry. Particular attention will be given to our latest results on the preparation of geopolymer type paste and concrete from fly ash. Mechanical activation of fly ash caused a decrease in porosity with a partial amorphisation of the crystalline constituents. Geopolymer type paste prepared from 30 minute milled Darkhan pond ash showed increase in 7 day compressive strengths by 7 times reaching of 15.4 (4.6) MPa. Keywords: Geopolymer binder, alkali-activated materials, coal combustion by products

Preparation and Properties of Pressed Metakaolin and Fly Ash Based Alkali-Activated Binders

2014 ◽  
Vol 897 ◽  
pp. 65-68 ◽  
Author(s):  
Jana Boháčová ◽  
Stanislav Staněk ◽  
Pavel Mec
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
High Temperatures ◽  
Frost Resistance ◽  
Raw Materials ◽  
Fly Ashes ◽  
Secondary Raw Materials ◽  
Alkali Activated Binders ◽  
Alkali Activated

Metakaolin, fly ashes and other secondary raw materials serves as suitable input in preparation of alkali-activated binders. This work deals with preparation of alkali-activated materials based on metakaoline and fly ash. Mixtures were prepared with a minimum of mixture water, ready for pressing. Prepared specimens were tested for tensile strength and pressure strength, resistance to high temperatures, frost resistance and resistance to water and salt.

scholarly journals Fire-resistant cellulose boards from waste newspaper, boric acid salts and protein binders

2021 ◽  
Author(s):  
Paalo Moreno ◽  
Nicole Villamizar ◽  
Jefferson Perez ◽  
Angelica Bayona ◽  
Jesús Roman ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Boric Acid ◽  
Building Materials ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Sustainable Construction ◽  
Load Bearing ◽  
Protein Binders

Abstract Housing construction consumes more materials than any other economic activity, with a total of 40.6 Gt/year. Boards are placed between construction materials to serve as non-load-bearing partitions. Studies have been performed to find alternatives to conventional materials using recycled fibers, agro-industrial waste, and protein binders as raw materials. Here, fire-resistant cellulose boards with low density and adequate flexural strength were produced for use as non-load-bearing partitions using waste newspapers, soy protein, boric acid, and borax. A central composite design (CCD) was employed to study the influence of the board component percentage on flame retardancy (UL 94 horizontal burning test), density (ASTM D1037-12) and flexural strength (ISO 178–2010). The cellulose boards were characterized by thermal analysis (ASTM E1131-14) and scanning electron microscopy. Fire-resistant cellulose boards were successfully made with low densities (120–170 kg/m3) and flexural strength (0.06–0.64 MPa). The mechanical performance and fire resistance of cellulose boards suggest their suitability for use as building materials. A useful and sustainable construction material with great potential is produced with the valorization of waste materials.

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