scholarly journals Experimental Investigation on Use of Wheat Straw Ash and Bentonite in Self-Compacting Cementitious System

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Rao Arsalan Khushnood ◽  
Syed Ali Rizwan ◽  
Shazim Ali Memon ◽  
Jean-Marc Tulliani ◽  
Giuseppe Andrea Ferro

In this research, we evaluated the feasibility of wheat straw ash and bentonite (raw and heated at 150°C for 8 hrs) as secondary raw materials in self-compacting paste (SCP). The fresh and hardened properties of SCP formulations including water and superplasticizer demand, flow behavior, compressive and flexural strength development, water absorption, and acid attack resistance were evaluated. Moreover, porosity, microstructural, and mineralogical investigations were also carried out on SCP formulations. Test results showed that the properties of SCP formulations in fresh state depend on the morphology of secondary raw materials. For heated bentonite and wheat straw ash formulations, the 28 days of compressive and flexural strength were higher or almost similar to reference SCP formulation. Among SCP formulations, wheat straw ash formulation was found to be more effective in consuming free lime and showed significant decrease in porosity with time, which in turn improved the resistance of this SCP formulation against water absorption and acid attack. Based on the test results, it can be concluded that the successful utilization of wheat straw ash and bentonite SCP formulations will offer durable and environmental friendly option to construction industry.

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Naraindas Bheel ◽  
Paul Awoyera ◽  
Irfan Ali Shar ◽  
Samiullah Sohu ◽  
Suhail Ahmed Abbasi ◽  
...  

Over the last decade, there has been a surge in research into possible cement substitute materials in concrete that are environmentally friendly, cost-effective, and socially beneficial. The alternatives include industrial and agricultural wastes, and their potential advantages can be achieved through recycling, repurposing, and renewing processes. With the use of these wastes as additional and replacement materials, significant energy savings and a reduction in cement use can be achieved, which helps to reduce carbon dioxide (CO2) emissions in the environment. Therefore, the use of rice husk ash (RHA) and wheat straw ash (WSA) as ternary cementitious material (TCM) in concrete can help reduce the impact on the environment and minimize the use of Portland cement (PC) in the concrete mixture. This research work is performed on the concrete blended with 0%, 5%, 10%, 15%, and 20% of RHA and WSA as TCM in the mixture. However, the purpose of this experimental work is to investigate the influence of RHA and WSA as TCM on the fresh (slump), physical (water absorption and density), and hardened properties (compressive strength, splitting tensile strength, and flexural strength) and drying shrinkage of concrete. In this regard, a total of 240 concrete samples (cylinders, cubes, and beams) were prepared with 1 : 2 : 4 mix proportions at 0.50 water-cement ratio and cured at 7 and 28 days, respectively. Moreover, the workability of green concrete is getting reduced as the quantity of TCM increases in the mixture. Besides, the compressive strength, splitting tensile strength, and flexural strength are enhanced by 12.65%, 9.40%, and 9.46% at 10% of TCM (5% RHA and 5% WSA) on 28 days consistently. Furthermore, the density and water absorption of concrete are reduced with the increase in the dosages of TCM on 28 days, respectively. In addition, the drying shrinkage is reduced with the increase in the quantity of TCM in concrete.


Cerâmica ◽  
2010 ◽  
Vol 56 (339) ◽  
pp. 285-290 ◽  
Author(s):  
P. Hettiarachchi ◽  
J. T. S. Motha ◽  
H. M. T. G. A. Pitawala

This study focuses on the identification of an appropriate composition of raw materials for ceramic products from commonly available red clays in Sri Lanka. The raw materials were characterized in terms of particle size distribution, chemical and mineralogical composition. Different formulations of samples were prepared, and the linear shrinkage, water absorption and flexural strength of the final products were measured. Microstructures of fired samples were observed under a scanning electron microscope. The best quality product was obtained when the sample contains a high amount of illite clay in a mixture of 80 wt.% clay-silt and 20 wt.% sand. The presence of higher concentrations of the metal oxides Na2O, K2O and Fe2O3 (total ~21 wt.%) in the clay-silt fraction of samples has resulted in obtaining higher technological properties of the body. The flexural strength and the water absorption of the product are 26.82 MPa and 6.51% respectively. If the raw materials contain lower amounts of the oxides Na2O, K2O and Fe2O3, higher amounts of clay-silt fraction (up to 90 wt.%) must be added to obtain an optimum quality product.


2019 ◽  
Vol 8 (3) ◽  
pp. 7736-7739 ◽  

This paper studies the effect of incorporating metakaolin on the mechanical properties of high grade concrete. Three different metakaolins calcined at different temperature and durations were used to make concrete specimens. Three different concrete mixtures were characterized using 20% metakaolin in place of cement. A normal concrete mix was also made for comparison purpose. The compressive strength test, split tensile test and flexural strength tests were conducted on the specimens. The compressive strength test results showed that all the metakaolin incorporated concrete specimens exhibited higher compressive strength and performed better than normal concrete at all the days of curing. The rate of strength development of all the mixes was also studied. The study revealed that all the three different metakaolin incorporated mixtures had different rate of strength development for all the days of hydration (3, 7,14, 28, 56 and 90), indicating that all the metakaolins possessed different rate of pozzolanic reactivity. Further, from the analysis of the test results, it was concluded that the variation in the rate of strength development is due to the differences in the temperature and duration at which they were manufactured. The results of split tensile strength test and the flexural strength test conducted on the specimens, supported the conclusions drawn from the results of compressive strength test. The paper also discusses, the rate of development of compressive strength and the pozzolanic behaviour of the metakaolins in light of their parameters of calcination and physical properties such as amorphousness and particle size. This paper has been written with a view to make the potential of metakaolin available to the construction industry at large


2021 ◽  
Vol 2021 ◽  
pp. 1-11 ◽  
Author(s):  
Naraindas Bheel ◽  
Samiullah Sohu ◽  
Paul Awoyera ◽  
Ashok Kumar ◽  
Suhail Ahmed Abbasi ◽  
...  

In the present era, a number of researchers are using either industrial or agricultural priceless products as a basic source of raw materials for the construction industry. These waste products are economical and helpful in producing a sustainable environment and reducing environmental pollution, which is called handling waste products. However, this research work was conducted on concrete containing 0.25%, 0.50%, 0.75%, and 1% of jute fiber as reinforcement material and 10%, 20%, 30%, and 40% of wheat straw ash (WSA) as replacement for fine aggregates. Moreover, the separate and combined effect of jute fiber and WSA as a replacement for sand ingredient in concrete is to determine the fresh and hardened properties of concrete. In this research, a number of concrete samples were prepared with 1 : 1.5 : 3 mix proportion at 0.54 water-cement ratio and cured at 28 days. The experimental outcomes displayed that the compressive, splitting tensile, and flexural strengths improved by 32.88 MPa, 3.80 MPa, and 5.30 MPa at 0.50% of jute fiber along with 30% of WSA at 28 days consistently. Similarly, the modulus of elasticity was developed while the dosages of jute fiber and WSA increased together in concrete. Moreover, the permeability and workability of concrete were reduced while utilized jute fiber and WSA increased together in concrete.


Cerâmica ◽  
2013 ◽  
Vol 59 (352) ◽  
pp. 609-613
Author(s):  
C. Sadik ◽  
A. Al Albizane ◽  
I. El Amrani

Production of porous and light-weight bricks with acceptable flexural strength is accomplished. Sawdust was used as an additive to an earthenware brick to produce the pores. SEM-EDS, XRD and XRF analysis of the raw materials and the elaborated refractory were performed. Mixtures containing sawdust were prepared at different proportions (up to 30%). Apparent porosity at 1600 °C was investigated with the bulk density, water absorption, firing shrinkage and flexural strength. Microstructural investigation was carried out by both natural light microscopy and polarized light microscopy. The results obtained showed that the samples tested here maintained their shape without undergoing any deformation up to 1600 °C. The use of sawdust decreased the fired density of the bricks down to 1.24 g/cm³.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 388
Author(s):  
Hamayoun Mahmood ◽  
Saqib Mehmood ◽  
Ahmad Shakeel ◽  
Tanveer Iqbal ◽  
Mohsin Ali Kazmi ◽  
...  

Glycerol pretreatment is a promising method for the environmentally-friendly transformation of lignocellulosic materials into sustainable cellulose-rich raw materials (i.e., biopolymer) to fabricate biocomposites. Here, a comparison of aqueous acidified glycerol (AAG) pretreatment of wheat straw (WS) with alkaline, hot water, and dilute acid pretreatments on the thermal and mechanical characteristics of their fabricated composite board is presented. A comparison of total energy expenditure during WS pretreatment with AAG and other solutions was estimated and a comparative influence of AAG processing on lignocellulosic constituents and thermal stability of WS fiber was studied. Results imply that AAG pretreatment was superior in generating cellulose-rich fiber (CRF) as compared to other pretreatments and enhanced the cellulose contents by 90% compared to raw WS fiber. Flexural strength of acidic (40.50 MPa) and hot water treated WS composite (38.71 MPa) was higher compared to the value of 33.57 MPa for untreated composite, but AAG-treated composites exhibited lower values of flexural strength (22.22 MPa) compared to untreated composite samples. Conversely, AAG pretreatment consumed about 56% lesser energy for each kg of WS processed as compared to other pretreatments. These findings recognize that glycerol pretreatment could be a clean and new pretreatment strategy to convert agricultural waste into high-quality CRF as a sustainable raw material source for engineered biocomposite panels.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 857
Author(s):  
Chao Fu ◽  
Chunyan Xie ◽  
Jing Liu ◽  
Xiuli Wei ◽  
Dake Wu

The application of nano-materials to modify construction materials has become a research hotspot in recent years, but often different scholars use different research methods and reach different conclusions about the same material, which is not conducive to the performance comparison between different materials. In this paper, nano-SiO2, carbon nanotubes (CNTs) and nanocrystalline cellulose (NCC) were used as raw materials to prepare cement-based composites to compare the effects of the three nanomaterials on the mechanical and water absorption properties under the same experimental conditions, and their principles were investigated via The scanning electron microscope (SEM), X-Ray Diffraction (XRD) and other microscopic analysis testing methods. At the same time, strength benefit indexes are introduced to comprehensively evaluate the economics of the strength improvement provided by the three kinds of nanomaterial. The results show that doping with nano-SiO2, CNTs and NCC can promote the hydration process of cement effectively. The composite material exhibits excellent mechanical properties at the macro level because of the nucleation and filling effect of nano-SiO2, and the bridging and strengthening effects of CNTs and NCC. The compressive strength increased by 45.13%, 28.31% and 44.19% at 7d, and 23.09%, 18.40% and 23.40% at 28d. The flexural strength of 7d increased by 31.00%, 36.22 and 54.81%, and 14.91%, 22.23% and 30.46% at 28d. The water absorption is SiO2 < NCC < CNTs, and the nano-SiO2 is lower than the other two materials at least 15.54%. CNTs group has the lowest compressive strength benefit, which is 16.91 yuan/m3, and the lowest flexural strength benefit is NCC, which is 3.59 yuan/m3.


2016 ◽  
Vol 861 ◽  
pp. 32-39
Author(s):  
Jakub Hodul ◽  
Jana Hodná ◽  
Rostislav Drochytka

Epoxy coatings are used mainly in the construction especially where it is necessary to increase the resistance of concrete floors against mechanical wear, to increase chemical resistance, to prevent dusting and to ensure hygienically clean environment. Epoxy coating is a composite material that consists of epoxy resin cured mainly by polyamine hardener and filler. As a filler is currently used pure silica sand Dorsilit ground to below 0.063 mm and for more demanding applications fine glass flakes with a high proportion of SiO2. The aim of this work is to experimentally examine the possibility of using secondary raw materials as fillers into three types of polymer epoxy coatings, where it seems the most appropriate utilization is waste glass with a high content of SiO2. Based on the evaluation of the test results of tensile properties, Shore hardness and temperature resistance the possibility of replacing the commonly used filler by finely ground waste glass is assessed.


2021 ◽  
Vol 3 (5) ◽  
Author(s):  
A. Nzeukou Nzeugang ◽  
D. Tsozué ◽  
B. Kagonbé Pagna ◽  
A. Balo Madi ◽  
A. Fankam Deumeni ◽  
...  

AbstractIn this study, clayey soils are characterized as backfill and potential fusible raw materials for engineering. Geotechnical tests (particle size distribution, Atterberg limits, densities) and chemico-mineralogical analyses (X-ray fluorescence, X-ray diffraction and Fourier transform infrared) were carried out on samples collected from field in the locality of Boulgou (North Cameroon) followed by the determination of mechanical properties of fired bricks (850–1200 °C). The excavations carried out have revealed a thick layer of clayey soils (~ 2 to 2.5 m) over a sandy layer. This clay formation presents some stratifications with limited influence variation in terms of mineralogy. Mean grain size distribution is dominated by sand (62–80%), clay (12–25%) and silt (6–9%). It corresponds to silty–clayey soils regarding their methylene blue values (3.3–5.6), with low plastic (13–22%) to high plastic (33%) characteristics. They are classified by USCS as clayey sand/silty clay, while one sample is a poorly graded sand (SP). Clay minerals observed are kaolinite (6–12%), montmorillonite (2–6%) and illite (8–10%). Those parameters associated with their fine nature and high compressibility make them suitable engineering applications for backfill material and barriers. From chemical analyses, relatively high contents in alkali and alkaline earth elements (~ 4 to 6%) to be used as potential fusible raw materials for fired bricks or gres ceramics were revealed. Bricks characteristics are varied: linear shrinkage (0.3 to 9%), bulk density (1.8 to 2.3 g/cm3), water absorption (19.7 to 1.3%) and flexural strength (0.3 to 17.4 MPa). Overall, the requirement for fired brick (< 20%) is met up by the water absorption values. As from 1050 °C, these soils are made suitable for brick-making with good characteristics (metallic sound, good cohesion and flexural strength).


2015 ◽  
Vol 752-753 ◽  
pp. 588-592 ◽  
Author(s):  
Chao Lung Hwang ◽  
Trong Phuoc Huynh

This paper reports on the potential use of fly ash (FA) and residual rice husk ash (RHA) in producing unfired building bricks (UBB) with the application of densified mixture design algorithm (DMDA) method. In this study, little amount of cement (10–15%) was added into the mixtures as binder substitution. Whereas, unground rice husk ash (URHA), an agricultural by-product, was used as partial aggregate replacement (10–20%) in the mixtures. The UBB of 220×105×60 mm in size were prepared and the hardened properties of the bricks were tested including compressive strength, flexural strength, water absorption and bulk density according to Vietnamese standard. Forming pressure of 35 MPa was applied to form the solid bricks in the mold. The test results show that all brick specimens achieved very good mechanical properties. The compressive strength, flexural strength and water absorption of brick specimens were respectively in range of 16.1–22.1 MPa, 2.8–3.5 MPa and 9.5–14.8% and the other properties of the bricks were well conformed to related Vietnamese standard. It was definitely proved many potential applications of FA and RHA in the production of UBB.


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