scholarly journals The use of aluminum slag waste in the preparation of roof tiles

Author(s):  
Marwa Ahmed ◽  
M. F. Abadir ◽  
Ayman Yousef ◽  
K. A. M. El-Naggar

Abstract Aluminum slag waste generated from the smelting process of bauxite was used to prepare roof tiles samples. Clay was substituted by slag waste in percentages reaching 40% in the basic mix and the plasticity of the obtained mud was determined. This was followed by pressing the mud in steel molds and drying. The effect of waste addition on drying shrinkage was subsequently assessed. Firing of the green bodies was carried out at three temperatures (900, 1000 and 1100oC) and hour soaking at each temperature. Fired roof tile properties improved on increasing the percentage of alumina sludge and firing temperature possibly because of the presence of high amounts of fluxing oxides in aluminum slag. This caused a drop in porosity that increased the mechanical strength of tiles. The results showed that the substitution of clay by 40% waste and firing at 1100oC resulted in products conforming to ASTM C-1167 for clay type roof tiles. Cold water absorption dropped to 12%, below the maximum permissible limit of 15%, the value of Saturation Coefficient was 0.83, below the 0.86 limit and the obtained breaking strength of 3370N significantly exceeded the minimum requirement of 890N.

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2535
Author(s):  
Ji-Bong Choi ◽  
Yu-Kyoung Kim ◽  
Seon-Mi Byeon ◽  
Jung-Eun Park ◽  
Tae-Sung Bae ◽  
...  

In this study, a hydrogel using single and double crosslinking was prepared using GelMA, a natural polymer, and the effect was evaluated when the double crosslinked hydrogel and tannic acid were treated. The resulting hydrogel was subjected to physicochemical property evaluation, biocompatibility evaluation, and animal testing. The free radicals generated through APS/TEMED have a scaffold form with a porous structure in the hydrogel, and have a more stable structure through photo crosslinking. The double crosslinked hydrogel had improved mechanical strength and better results in cell compatibility tests than the single crosslinked group. Moreover, in the hydrogel transplanted into the femur of a rat, the double crosslinked group showed an osteoinductive response due to the attachment of bone minerals after 4 and 8 weeks, but the single crosslinked group did not show an osteoinductive response due to rapid degradation. Treatment with a high concentration of tannic acid showed significantly improved mechanical strength through H-bonding. However, cell adhesion and proliferation were limited compared to the untreated group due to the limitation of water absorption capacity, and no osteoinduction reaction was observed. As a result, it was confirmed that the treatment of high-concentration tannic acid significantly improved mechanical strength, but it was not a suitable method for improving bone induction due to the limitation of water absorption.


Eksergi ◽  
2015 ◽  
Vol 12 (1) ◽  
pp. 08
Author(s):  
Wasir Nuri ◽  
Dyah Tri Retno

Lapindo mudflow issued a very large volume of mud. The mud flooded rice fields, residential and industrial area to date has not been stopped but the mud bursts untapped yet. Therefore, attempted use Lapindo mud very much it to be made tile. Sludge containing 55.4% silica oxide, alumina 16.1% and 8.9% iron with the composition of the possibility of mud can be created tile roof. Dried mud that has been mashed into the grain size of 80 mesh, then water added until plastic. Mud that has plastic printed with size 6 x 3 x 3 cm and then dried using ambient air. After the dried samples were burned using a furnace at temperatures varying from 500 to 900oC, after chilling the samples tested compressive strength, fracture modulus and water absorption. The results showed that the higher the combustion temperature obtained greater compressive strength and less water absorption. Most compressive strength is 142 kg/cm2and smallest water absorption is 0.06 g/cm2at a temperature of 900oC. At combustion temperatures of 500 to 700oC fracture modulus down from 72.78 to 41.81 kg/cm2 while at 700 to 900oC fracture modulus rose to 126.7 kg/cm2. The best results obtained on the combustion temperature at 800oC with fracture modulus 103.18 kg/cm2 and water absorption 0.08 g/cm2.   These results satisfy roof tile as type I according SII.0027 UDC-81. 666.74.


2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Chai Teck Jung ◽  
Tang Hing Kwong ◽  
Koh Heng Boon

Abstract: This paper presents some experimental results and discusses the used of recycled foamed aggregates as natural coarse aggregates replacement in producing concrete. The physical properties of recycled foamed aggregates concrete were investigated. The properties studied are water absorption and drying shrinkage from the concrete early ages until the periods of 56 days. The 100 mm x 100 mm cube specimen was used to study the water absorption at the age of 7, 28 and 56 days. Meanwhile, the 100 mm x 100 mm x 300 mm length prism had been casted and used for drying shrinkage test for recycled foamed aggregates concrete. The foamed aggregates was produced from crushing recycled foamed concrete blocks. It were coated with cement paste to reduce its water absorption ability during casting process. Superplasticizer was used to maintain the workability of fresh concrete with a slump vary between 50 mm to 100 mm. The physical tests were conducted on recycled foamed aggregates to determine their initial properties such as loose bulk density, sieve analysis and water absorption rate. Recycled foamed aggregate concretes were produced with varied water cement ratio. The results obtained indicated that the linear elastic relationship between water cement ratio and water absorption rate. The higher the water cement ratio of concrete specimen will obtained higher water absorption rate. Vice versa, the density is low for drying shrinkage. The water absorption decreased while drying shrinkage becomes more stabilized over curing period.


Author(s):  
Nguyen Van Chinh

Drying shrinkage is the main cause of early age cracking of concrete and mortar. A wide range of research has been conducted to reduce the drying shrinkage, including using fibres or chemical admixtures. This paper investigated the effect of shrinkage reducing admixture on the flexural strength, compressive strength, drying shrinkage, water absorption and porosity of mortar. The mix compositions were ordinary Portland cement (OPC) : sand : liquid = 1: 1: 0.38 in which liquid consisted of water and shrinkage reducing admixture (SRA). SRA was used at the proportions of 2%, 4%, and 7% by weight of cement. The test results show that SRA reduces the flexural and compressive strengths of mortar. The reduction in flexural strength and compressive strength at 28 days is 14% and 25%, respectively at 7% SRA dosage. In addition, SRA significantly reduces the drying shrinkage and water absorption of mortar. At 7% SRA dosage, the drying shrinkage at 53 days is reduced by 60% while the water absorption rate at 24 hours is reduced by 54%. However, SRA has a minor effect on the pore size distribution, effective porosity, and cumulative intrusion volume of mortar.


2010 ◽  
Vol 152-153 ◽  
pp. 1650-1659
Author(s):  
Qing Hao Yang ◽  
Guang Xu Cheng ◽  
Zhi Cheng Zhang

In an effort to seek poly(vinyl formal) (PVFM) foams based wound dressing pad material, a series of foamed PVFM materials have been synthesized under varied conditions. The influence of conditions on the properties of PVFM foam, such as mechanical properties, water absorption, pore structure and bulk density, is well discussed individually. It has been shown that both the reactant and acid catalyst affect the degree and speed of acetalization, therefore the mechanical properties, pores continuity and water absorption of the resultant sample. The addition of Na2CO3, surfactant and CMCNa are mainly influencing the porous structure as well as the mechanical properties and water absorption. One best sample with balanced properties is obtained. It possesses higher mechanical strength and water absorption while the other properties are similar, comparing with a commercial surgical PVFM sponge (YJ-1) currently used.


Recycling ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 29
Author(s):  
Alhagie Bakary Ceesay ◽  
Shingo Miyazawa

The use of recycled aggregate in new concrete has often been limited due to concerns over their quality and structural performance. This research aims to investigate the physical properties of recycled roof tile aggregate and its suitability for concrete production. Physical properties of recycled roof tile aggregate are compared to normal crushed stone aggregate. Effects of recycled roof tile aggregates on strength and durability of recycled roof tile concrete was compared with normal aggregate concrete using mechanical properties and durability tests. The experimental results showed that high water absorption and low strength of aggregate have a great effect on the workability and strength of the concrete containing recycled roof tile aggregate. Aggregate density, water absorption, crushing value and abrasion value of the recycled roof tile aggregate were found to be lower than crushed stone aggregate and concrete containing recycled roof tile aggregate had low strength and slow strength development. Similar durability performance of recycled roof tile aggregate concrete and normal aggregate concrete was observed except when exposed to freezing and thawing.


2014 ◽  
Vol 61 (3) ◽  
pp. 143-150 ◽  
Author(s):  
A. Al-Swaidani ◽  
S. Aliyan ◽  
N. Adarnaly ◽  
B. Hanna ◽  
E. Dyab

Abstract In the study, three types of cement have been prepared; one CEM I type (the control sample) and two blended cements: CEM II/A-P and CEM II/B-P (EN 197-1), each of them with three replacement levels of volcanic scoria: (10 %, 15 %, 20 % wt.) and (25 %, 30 %, 35 % wt.), respectively. Strength development of mortars has been investigated at 2, 7, 28 and 90 days curing. Evaluation of chemical resistance of mortars containing scoria-based cements has been investigated through exposure to 5 % sulphate and 5 % sulphuric acid solutions in accordance with ASTM C1012 & ASTM 267, respectively. Drying shrinkage has been evaluated in accordance with ASTM C596. Test results showed that at early ages, the mortars containing CEM II/B-P binders had strengths much lower than that of the control mortar. However, at 90 days curing, the strengths were comparable to the control mortar. In addition, the increase of scoria significantly improved the sulphate resistance of mortars. Further, an increase in scoria addition improved the sulphuric acid resistance of mortar, especially at the early days of exposure. The results of drying shrinkage revealed that the CEM II/B-P mortar bars exhibited a greater contraction when compared to the control mortar, especially at early ages. However, drying shrinkage of mortars was not influenced much at longer times.


2002 ◽  
Vol 712 ◽  
Author(s):  
Antonia Moropoulou ◽  
Asterios Bakolas ◽  
Petros Moundoulas ◽  
Eleni Aggelakopoulou ◽  
Sofia Anagnostopoulou

ABSTRACTCement based mortars used for historic masonry restoration presented unsatisfactory results, due to their chemical and physico-mechanical incompatibility to original buildings. In the present research, several syntheses of restoration mortars are produced using traditional techniques and materials such as binders (aerial and natural hydraulic lime), pozzolanicadditives (natural and artificial pozzolanas) and aggregates (sand and crushed brick). The technical characteristics of the mortars were determined using mechanical tests (compressive and flexural) and mercury intrusion porosimetry measurements at the time of 1, 3, 9, 15 months of curing. Water absorption measurements were performed at the time of 9 and 15 months curing, in order to evaluate mortars microstructural characteristics, their rate of water absorption and the total percentage of absorbed water. The aerial lime - artificial pozzolana mortar presented the best mechanical and microstructural performance. Hydraulic mortars acquired the maximum of the mechanical strength in 1 month, lime - pozzolana mortars in 3 months while aerial lime mortars continue to gain mechanical strength even in 15 months curing. Furthermore, the use of ceramic aggregates produces lightweight and elastic mortars, compatible to historicones.


2015 ◽  
Vol 75 (5) ◽  
Author(s):  
Farah A. Hadi ◽  
Hanizam Awang ◽  
Muhammed Zuhear Almulali

This paper investigates the effect of replacing different portions of cement by fine oil palm ash (FOPA). A target density of 1000 kg/m3 was used for the foamed concrete mixes. A foamed concrete mix of 1 part binder, 2 parts filler and 0.45 part of water has been used. Cement was replaced at levels of 25, 35, 45, 55 and 65% by weight of binder. The compressive strength, density, water absorption, drying shrinkage and sorptivity were tested at different ages. The mix containing 25% of fine OPA showed enhanced properties in comparison to the control mix at the age of 90 days. The mixed showed higher compressive strength, less water absorption, increased density and lesser sorptivity. However, the same mix showed higher shrinkage readings than that of the control mix. 


2012 ◽  
Vol 550-553 ◽  
pp. 2373-2377
Author(s):  
Wei Juan Guo ◽  
Gao Xiang Du ◽  
Ran Fang Zuo ◽  
Jing Hui Liao

his paper studies the feasibility of preparation high strength fired bricks from iron tailings with addition of clay and coal gangue. The results indicated that the optimum conditions were found to be that the hematite tailings content were 35%–50%; the firing temperature was 1000 °C. Under these conditions, the mechanical strength, the water absorption and the bulk density of the fired bricks were 21.17–26.14 MPa, 14.55–15.47% and 1.648–1.629g/cm3, respectively, these were well conformed to standards MU20 of Chinese Fired Common Bricks Standard (GB/T5101-2003).The phase composition and microstructure of the fired specimen were characterized by XRD and SEM. The results showed that the major crystalline phases present in fired brick were quartz, albite, amphibole, hematite and muscovite, and glass phase encapsulated and cement the crystalline phases forming strong entirety which promoted the strength of bricks.


Sign in / Sign up

Export Citation Format

Share Document