Effects of Lightweight Aggregate Size and Grading on the Residual Strength of Lightweight Geopolymer Concrete Exposed to Elevated Temperature

2014 ◽  
Vol 803 ◽  
pp. 3-10
Author(s):  
Omar A. Abdulkareem ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Khairul Nizar Ismail

The lightweight aggregate geopolymer concrete (LWAGC) systems were prepared using a lightweight aggregate (LWA) of different size and grading. The diversity in the LWA size and grading led to various physical properties like oven-dry (OD) density, water absorption and total porosity characteristics for the resultant LWAGCs. These physical properties were significantly affected and controlled thermal behavior of the concretes after exposure to elevated temperature of 800 °C. The results of the mechanical and physical test conducted to the unexposed LWAGCs showed that the OD-density and compressive strength increased as the LWA maximum and minimum size decreased. In contrast, the water absorption and total porosity of the unexposed LWAGC were increased with increasing of the LWA maximum and minimum size. Thus, the lowest OD-density LWAGC possessed the highest water absorption and total porosity which resulted in lowest compressive strength, whereas, it has the minimal strength loss after exposure to the elevated temperature. The water absorption and total porosity of the unexposed LWAGCs were indirectly implies the permeability characteristics of the concretes which is controllers the thermal behavior of the LWAGC at elevated temperatures.

2020 ◽  
Vol 39 (3) ◽  
pp. 732-737
Author(s):  
S. Gambo ◽  
K. Ibrahim ◽  
A. Aliyu ◽  
A.G. Ibrahim ◽  
H. Abdulsalam

Due to the carbon dioxide emission arising from the production of cement, alternative concrete that is environmentally friendly such as metakaolin geopolymer concrete have been developed. However, the performance of metakaolin based geopolymer concrete (MKGC) when exposed to aggressive environment particularly elevated temperature has not been investigated. Therefore, this paper assessed the performance of MKGC exposed to elevated temperatures. MKGC cube specimens of grade 25 were produced using a mix ratio of 1:1.58:3.71.After preparing the specimens, they were placed in an electric oven at a temperature of 60oC for 24 hours. Thereafter, the specimens were stored in the laboratory at ambient temperature for 28 days. The specimens were then exposed to elevated temperatures of 200, 400, 600 and 800oC. After exposure to elevated temperatures, the MKGC specimens were subjected to compressive strength, water absorption and abrasion resistance tests. Results show that at 600 and 800oC, the MKGC lost a compressive strength of 59.69% and 71.71% respectively. Higher water absorption and lower abrasion resistance were also observed. Keywords: Cement, Compressive Strength, Metakaolin Concrete, Elevated Temperature.


2008 ◽  
Vol 5 (4) ◽  
pp. 538-544
Author(s):  
Baghdad Science Journal

Nahrawan clay deposits lies in Diyala governorate , 65 Km, NE of Baghdad , according to the previous work in this field, in which they study the reserve belong to category of investigation ( C2 & C1 ) , we choice the proper area to investigation of category (B) with drill net( 200x 200m ) to rise the amount of reserve. The investigation work included drilling (116) boreholes of total depth ranges from (10.0-12.55m) , showed mainly clayey and silty deposits with little sand , and the typical borehole (648) represents all types of sediment in the area , and most of boreholes without sandy deposits , and all of these deposits is Quaternary sediment which is consist of two main sedimentary cycles ( the Pleistocene & Holocene ) . Chemical analysis for (343) samples were done , and physical test carried on ( 143 ) samples , and all show suitable properties for clay brick industry . the area of investigation covered ( 5.200.000 m2) involving ( 620.000 m2 ) containing soluble salt more than ( 3.5%) , which was separated from the total area , so the residual (4.580.000m2 ) had been taken to calculate the reserve , with depth of ( 10.76m) for the industrial clay bed . The reserve calculations depended on the following chemical & physical Properties: The chemical analysis shows that , CaO ( 16.53%) MgO ( 4.65% ) , SO3 ( 1.42%) , T.S.S. (2.42%) , the physical properties are unfired properties Which contains Bulk density ( 2.09gm/cm3) , moisture content (20.95%) , linear dry shri. (7.63%) , and fired properties which contain water absorption (18.8%) , linear shri. (0.8%) volume shri. (2.212% ) , compressive strength ( 468.606Kg/cm2) . So the reserve of category (B) is ( 49.280. 800 m3 ) or (102.966.000 Ton) the physical test showed that the brick classified into class (A-B) .


2019 ◽  
Vol 801 ◽  
pp. 365-370
Author(s):  
Vivek Sood ◽  
S.K. Negi ◽  
B.M. Suman

In the present study, use of marble dust an inert filler produced by the marble cutting industries in the development of light weight block (LWB) of density 800 kg/m3 by non-auto clave method has been studied. Various mechanical and thermo-physical properties have been evaluated. It has been possible to replace cement by up to 20% when no additive is used. With the use of activator and super plasticizer at 50% replacement of cement by marble dust, compressive strength and water absorption are well within the Indian standard code 2185. With the use of accelerator and super plasticizer it is possible to reduce the de moulding time from 48 hrs to 6 hrs. Thermal conductivity of blocks varies from 1.16 to 2.30 [W/mK]. The variation in thermal conductivity depends upon its density which varies from 800 kg/m3 to 2400 kg/m3.


2014 ◽  
Vol 92 ◽  
pp. 68-73
Author(s):  
Yancho Hristov ◽  
Yordan Kostadinov ◽  
Plamen Pashev ◽  
Bogdan Bogdanov

A lightweight inorganic polymer is obtained using by ash from thermal power plants and lightweight aggregate from perlite . This inorganic material is activated using small amounts of sodium hydroxide and sodium silicate solution. In addition, porosity and water absorption were determined. Results showed that the lightweight geopolymer blocks with satisfactory strength and density could be made. The 28-day compressive strength of 5.2–13.8 MPa, density of 1075–1345 kg/m3, water absorption of 10–28% and porosity of 15–32% obtained. It can be used as lightweight geopolymer concrete for partition walls.


2014 ◽  
Vol 711 ◽  
pp. 166-169
Author(s):  
Jing Li ◽  
Guo Zhong Li

Polystyrene granules (EPS) for lightweight aggregate and cement for cementing material, while adding a variety of additives, were used to prepare cement-based composite thermal insulation materials by the method of vibration molding. The effects of different waterproof agent on water absorption and strength of cement-based composite thermal insulation materials were studied contrastively by adding emulsified stearic acid and emulsified composite waterproofing agent, and the related mechanisms were analyzed. Results showed that the waterproofing effect and strengthen effect of emulsified composite waterproofing agent is superior to emulsified stearic acid, when the content of emulsified stearic acid and emulsified composite waterproofing agent are 5% and 5%, respectively, the 2h, 24h water absorption of samples are 20.59%, 47.64% and 15.53%, 34.53%, the flexural and compressive strength of samples are 0.32MPa, 0.42MPa and 0.35MPa, 0.47MPa.


2017 ◽  
Vol 888 ◽  
pp. 37-41
Author(s):  
Hasrul Yahya ◽  
Mohd Roslee Othman ◽  
Zainal Arifin Ahmad

Porcelain balls as grinding media are produced by firing process of clay, quartz and feldspar mixtures. This application need high technological properties such as high compressive strength and hardness, wear resistance, low water absorption and excellent chemical resistance. These properties are associated with higher firing temperatures. The porcelain balls were prepared by mixing 30 wt.% clay, 40 wt.% feldspar and 30 wt.% quartz. The samples were sintered at 1200°C, 1230°C, 1250°C, 1270°C and 1300°C for 2 hours with heating rate of 3°C/min. Both green powder and fired samples were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM).The properties of the fired samples were evaluated by compressive strength, hardness, shrinkage, water absorption, bulk density, and porosity measurement. Increasing of compressive strength, hardness and density are associated with increasing of firing temperatures. Porcelain balls PB1 and PB2 can be produced as grinding media with optimum mechanical and physical properties at firing temperature 1270°C and 1250°C, respectively.


2018 ◽  
Vol 162 ◽  
pp. 02024
Author(s):  
Waleed Abbas ◽  
Wasan Khalil ◽  
Ibtesam Nasser

Due to the rapid depletion of natural resources, the use of waste materials and by-products from different industries of building construction has been gaining increased attention. Geopolymer concrete based on Pozzolana is a new material that does not need the presence of Portland cement as a binder. The main focus of this research is to produce lightweight geopolymer concrete (LWGPC) using artificial coarse lightweight aggregate which produced from locally available bentonite clays. In this investigation, the binder is low calcium fly ash (FA) and the alkali activator is sodium hydroxide and sodium silicate in different molarities. The experimental tests including workability, fresh density, also, the compressive strength, splitting tensile strength, flexural strength, water absorption and ultrasonic pulse velocity at the age of 7, 28 and 56 days were studied. The oven dry density and thermal conductivity at 28 days age are investigated. The results show that it is possible to produce high strength lightweight geopolymer concrete successfully used as insulated structural lightweight concrete. The 28-day compressive strength, tensile strength, flexural strength, dry density, and thermal conductivity of the produced LWGPC are 35.8 MPa, 2.6MPa, 5.5 MPa, 1835kg/m3, and 0.9567 W/ (m. K), respectively.


Abstract In this study, vermicompost is replaced for fine aggregate in geopolymer concrete (GPC). Initially mix design is made for GPC and mix proportion is proposed. The vermicompost is replaced at 5%, 10%, 15% and 20% with M sand in GPC. Result indicates the 5% replacement with vermicompost based geopolymer concrete (GPVC) has the compressive strength of 32 N mm−2 (M30 grade) whereas the compressive strength of control specimen made with GPC is 37 N mm−2. Other replacement shows 21 N mm−2, 14 N mm−2 and 11 N mm−2 respectively. The 5% replaced concrete cubes and control specimen are tested at an elevated temperature of 200°C, 400°C, 600°C and 800°C and compared with the control specimen. There is no significant difference observed in weight lost at control (GPC) and GPVC specimen. An elevated temperature, the weight loss is almost 4% at 200°C because of expulsion of water from the concrete. Afterwards only 2% weight loss is observed in remaining elevated temperature. The compressive strength loss is observed at an elevated temperature in GPC and GPVC specimen because of thermal incompatibility between aggregate and the binder. EDX results show M sand and compost contains Si, Al, C, Fe, Ca, Mg, Na and K and it is similar in the elemental composition and SEM image confirms vermicompost contains fine particles.


2019 ◽  
Vol 70 (11) ◽  
pp. 4021-4028 ◽  
Author(s):  
Liew Yun Ming ◽  
Andrei Victor Sandu ◽  
Heah Cheng Yong ◽  
Yuyun Tajunnisa ◽  
Siti Fatimah Azzahran ◽  
...  

This paper investigates the effect of incorporation of lightweight aggregate and foam in the preparation of lightweight aggregate geopolymer concrete (LWAGC) and lightweight aggregate foamed geopolymer concrete (LWAFGC). The geopolymer paste was formed by alkali activation of Class F fly ash in mixture of sodium silicate and sodium hydroxide solution. LWAGC was incorporated with expanded clay lightweight aggregate and river sand while hydrogen peroxide was added as foaming agent for LWAFGC. Results showed that LWAGC and LWAFGC achieved an excellent 28-day compressive strength of 60 MPa and 20 MPa, respectively. The bulk densities were 1815 kg/m3 for LWAGC and 1593 kg/m3 for LWAFGC. Even so, low thermal conductivity of 0.12 W/mK and 0.09 W/mK were reported. It was concluded that the joint effect of lightweight aggregate and foam produced geopolymer concrete with good mechanical strength while having excellent thermal insulating properties. The geopolymer concretes possessed high strength-to-density ratio to be regarded as lightweight high-performance structures.


2020 ◽  
Vol 38 (11A) ◽  
pp. 1706-1716
Author(s):  
Wasan I. Khalil ◽  
Qias J. Frayyeh ◽  
Mahmood F. Ahmed

The purpose of this work is to investigate the possibility to recycled and reused of waste clay brick and waste plastic as constituents in the production of green Geopolymer concrete paving bricks. Powder of clay brick waste (WBP) was used as a partial replacement of Metakaolin (MK) in Geopolymer binder. Moreover, recycled clay brick waste aggregate (BA) and plastic waste aggregate (PL) were incorporated as coarse aggregate in mixtures of Metakaolin based Geopolymer concrete (MK-GPC) pavement bricks. Six types of mixtures were prepared and cast as pavement bricks with dimensions of 150×150×100 mm. All samples have been tested for compressive strength, water absorption and abrasion resistance at age of 28 days; and compared the results with the requirements of Iraqi specification No.1606-2006. The MK-GPC pavement bricks present a compressive strength of 31-47MPa, water absorption of 3.66% to5.32% and abrasion resistance with groove length between 21.78mm to 18.91 mm. These types of pavement bricks are classified as a medium to light capacity for weight loading, and it is possible to be used in wide range of paving applications, especially in aggressive wearing environment.


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