scholarly journals Feasibility study of compost as a partial substitute for fine aggregate in concrete

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.

2014 ◽  
Vol 567 ◽  
pp. 369-374 ◽  
Author(s):  
Nasir Shafiq ◽  
Asma Abd Elhsameed ◽  
Muhd Fadhil Nuruddin

In this study, the effect of sugar cane bagasse ash (SCBA) on chloride penetration resistance of concrete was investigated. 100-mm side cubes were cast and cured in water for 28 days followed by six months curing in 4% NaCl solution. The resistance to chloride penetration was assessed by measuring the chloride penetration depth, weight loss, compressive strength loss and bond strength loss. Chloride penetration depth was measured using AgNO3–based method. It was obtained that inclusion of SCBA in concrete significantly reduced the chloride penetration depth, weight loss, compressive strength loss and bond loss that was attributed to the fine particles of SCBA that filled up the pores and prevented the chloride ingress in the concrete.


2019 ◽  
Vol 2 (2) ◽  
pp. 65
Author(s):  
Purwanto P. ◽  
Himawan Indarto

Portland cement production process which is the conventional concrete constituent materials always has an impact on producing carbon dioxide (CO2) which will damage the environment. To maintain the continuity of development, while maintaining the environment, Portland cement substitution can be made with more environmentally friendly materials, namely fly ash. The substitution of fly ash material in concrete is known as geopolymer concrete. Fly ash is one of the industrial waste materials that can be used as geopolymer material. Fly ash is mineral residue in fine grains produced from coal combustion which is mashed at power plant power plant [15]. Many cement factories have used fly ash as mixture in cement, namely Portland Pozzolan Cement. Because fly ash contains SiO2, Al2O3, P2O3, and Fe2O3 which are quite high, so fly ash is considered capable of replacing cement completely.This study aims to obtain geopolymer concrete which has the best workability so that it is easy to work on (Workable Geopolymer Concrete / Self Compacting Geopolymer Concrete) and obtain the basic characteristics of geopolymer concrete material in the form of good workability and compressive strength. In this study, geopolymer concrete is composed of coarse aggregate, fine aggregate, fly ash type F, and activators in the form of NaOH and Na2SiO3 Be52. In making geopolymer concrete, additional ingredients such as superplastizer are added to increase the workability of geopolymer concrete. From this research, the results of concrete compressive strength above fc' 25 MPa and horizontal slump values reached 60 to 80 centimeters.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Tao Long ◽  
Qingyuan Wang ◽  
Zhongwei Guan ◽  
Yu Chen ◽  
Xiaoshuang Shi

Fly ash geopolymer concrete (FAGC) and ordinary Portland cement concrete (OPCC) specimens were immersed in 5% MgSO4solution undergoing 32 wetting-drying and heating-cooling cycles. Their compressive behavior was investigated after every 8 cycles. Several microstructure analysis techniques were applied on the samples to identify the materials formed due to magnesium sulfate attack, including XRD, FTIR, SEM, and EDS. Experimental results elucidated that the compressive strength loss ratio in the heating group of FAGC was 12.7%, while that of OPCC was 17.8%, which means that FAGC had better magnesium sulfate resistance than OPCC. The compressive strength loss of OPCC was due to the formation of gypsum under the magnesium sulfate attack exposed to wetting-drying and heating-cooling cycles. The deterioration mechanisms of FAGC against MgSO4solution were discovered to be that sodium aluminum silicate hydrate (N-A-S-H) gels reacted with MgSO4, leading to the creation of low strength magnesium aluminum silicate hydrate (M-A-S-H) gels.


2014 ◽  
Vol 8 (1) ◽  
pp. 444-449
Author(s):  
Lei Jiang ◽  
Ditao Niu

The damage evolution of concrete subjected to drying-wetting cycles in different concentration of sodium sulfate solution was investigated based on micro and macro-observations. Through the experiment, weight loss, compressive strength loss and the damage layer thickness of concrete were measured after different drying-wetting cycles. The mechanical properties degradation in the damage layer of concrete was also analyzed. Furthermore, the scanning electron microscopy and X-ray diffraction were used to investigate the corrosion products of concrete, and the damage mechanism was also investigated by the modern microanalysis techniques. The test results show that the deterioration degree of physical properties of concrete specimens increases with increasing concentration. Weight loss of specimens caused by sulfate attack is not obvious compared with the other evaluation index. When the damage layer thickness of concrete is thicker as well as the ultrasonic speed is lower, indicating that the deterioration degree of concrete increases, and the compressive strength loss in damage layer is serious. It was also found that the compressive loss of concrete is correspond with the observations for the damage layer thickness. Additionally, the main corrosion products of concrete in sulfate solutions subjected to drying-wetting cycles were confirmed to be ettringite and gypsum, and the quantity of corrosion products formed is proportional to the concentration of the solution.


2021 ◽  
Vol 15 (3) ◽  
pp. 8344-8355
Author(s):  
B. W. Chong ◽  
R. Othman ◽  
P. J. Ramadhansyah ◽  
S. I. Doh ◽  
Xiaofeng Li

With the increasing number of vehicle due to the boom of population and rapid modernisation, the management of waste tire is growing problem. Reusing grinded tire rubber in concrete is a green innovation which provide an outlet for reusing waste tire. While providing certain benefits to concrete, incorporation of tire rubber results in significant loss of concrete compressive strength which hinders the potential of rubberised concrete. This paper aims to develop mathematical models on the influence of tire rubber replacement on the compressive strength of concrete using design of experiment (DoE). 33 data sets are gathered from available literature on concrete with waste tire rubber as partial replacement of fine aggregate. Response surface methodology (RSM) model of rubberised concrete compressive strength shows great accuracy with coefficient of determination (R2) of 0.9923 and root-mean-square error (RMSE) of 2.368. Regression analysis on the strength index of rubberised concrete shows that rubberised concrete strength loss can be expressed in an exponential function of percentage of replacement. The strength loss is attributed to morphology of rubber particles and the weak bonds between rubber particles and cement paste. Hence, tire rubber replacement should be done sparingly with proper treatment and control to minimise concrete strength loss.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Djedjen Achmad ◽  
Desi Supriyan

ABSTRACTHas been researched the impact of mud in aggregate on geopolymer concrete with studies using the cement concrete as a reference. In this study both of concrete are mixed with a variation of mud of 0%, 0.75%, 3% and 5.75% of the combined aggregate weight. Compressive strength of cement concrete is designed with a target of 300 kg / cm2 and geopolymer concrete is made with water binder ratio (w/b) 0.25, Molarity 12 M, the ratio of sodium silicate and sodium hydroxide 1.5. At the age of 3, 7, 14 and 28 day tested of compressive strength, while the spliting test, flexural tensile strength, and modulus of elasticity are tested at 28 days. From the test results, the higher mud content in aggregate , the mechanical properties of the concrete are decreased. Based on testing of compressive strength in cement concrete at 28 days, with a 3% mud content (the content of the reference mud) turns of compressive strength decreased by 77.356%. Of the percentage reduction on the compressive strength of the cement concrete, can be compared to the mud content in geopolymer concrete at 2.04%. Thus the maximum mud on geopolymer concrete aggregate is, for coarse aggregate of 0.68% and a maximum mud content for fine aggregate was 3.4%.Key words : Mud, aggregate, concrete, cement, geopolimer, strengthABSTRAKTelah diteliti dampak kadar lumpur pada agregat untuk beton geopolimer dengan penelitian menggunakan benda uji beton semen sebagai acuan dan beton geopolimer. Dalam penelitian ini ke dua beton tersebut dicampur dengan lumpur gabungan agregat kasar dan agregat halus dengan variasi 0 %, 0.75 %, 3 % dan 5,75 % dari berat agregat gabungan. Beton semen dirancang dengan target kuat tekan 300 kg/cm2 dan beton geopolimer dibuat dengan campuran water binder ratio (w/b) 0.25, Molaritas 12 M, perbandingan sodium silikat dan sodium hidroksida 1.5. Pada umur 3, 7, 14 dan 28 hari dilakukan uji kuat tekan, sedangkan uji kuat tarik belah, uji kuat tarik lentur, dan modulus elastisitas dilakukan pada umur 28 hari. Dari hasil uji terlihat bahwa semakin tinggi kadar lumpur pada agregat, karakteristik mekanis kedua beton tersebut mengalami penurunan. Berdasarkan pengujian kuat tekan pada beton semen umur 28 hari, dengan kadar lumpur 3 % (kadar lumpur referensi) ternyata beton semen mengalami penurunan kuat tekan sebesar 77.356 %. Dari persentase penurunan kuat tekan beton semen tersebut, diplot pada grafik kuat tekan beton geopolimer maka persentase kadar lumpur gabungan yang mengalami penurunan 77.356 % adalah 2.04 %. Dengan demikian kadar lumpur maksimum pada agregat beton geopolimer adalah, untuk agregat kasar sebesar 0.68 % dan kadar lumpur maksimum untuk agregat halus adalah 3.4 %.Kata kunci : Lumpur, agregat, beton, semen, geopolimer, kekuatan


Activated Slag (AAS) and Fly Ash (FA) based geopolymer concrete a new blended alkali-activated concrete that has been progressively studied over the past years because of its environmental benefits superior engineering properties. Geopolymer has many favorable characteristics in comparison to Ordinary Portland Cement. Many base materials could be utilized to make geopolymer with the convenient concentration of activator solution. In this study, the experimental program composed of two phases; phase on divided into four groups; Group one deliberated the effect of sodium hydroxide molarity and different curing condition on compressive strength. Group two studied the effect of alkali activated solution (NaOH and Na2SiO3) content on compressive strength and workability. The effect of sand replacement with slag on compressive strength and workability was explained in group three. Group four studied the effect of slag replacement with several base materials Fly Ash (FA), Ordinary Portland Cement (OPC), pulverized Red Brick (PRB), and Meta Kaolin (MK). Phase two contains three mixtures from phase one which had the highest compressive strength. For each mixture, the fresh concrete test was air content. In addition the hardened concrete tests were the compressive strength at 3, 7, 28, 90, 180, and 365 days, the flexural strength at 28, 90, and 365 days, and the young's modulus at 28, 90, and 365 days. Moreover; the three mixtures were exposed to elevated temperature at 100oC, 300oC, and 600oC to study the effect of elevated temperature on compressive and flexural strength.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6890
Author(s):  
Muhammad Ibraheem ◽  
Faheem Butt ◽  
Rana Muhammad Waqas ◽  
Khadim Hussain ◽  
Rana Faisal Tufail ◽  
...  

The purpose of this research is to study the effects of quarry rock dust (QRD) and steel fibers (SF) inclusion on the fresh, mechanical, and microstructural properties of fly ash (FA) and ground granulated blast furnace slag (SG)-based geopolymer concrete (GPC) exposed to elevated temperatures. Such types of ternary mixes were prepared by blending waste materials from different industries, including QRD, SG, and FA, with alkaline activator solutions. The multiphysical models show that the inclusion of steel fibers and binders can enhance the mechanical properties of GPC. In this study, a total of 18 different mix proportions were designed with different proportions of QRD (0%, 5%, 10%, 15%, and 20%) and steel fibers (0.75% and 1.5%). The slag was replaced by different proportions of QRD in fly ash, and SG-based GPC mixes to study the effect of QRD incorporation. The mechanical properties of specimens, i.e., compressive strength, splitting tensile strength, and flexural strength, were determined by testing cubes, cylinders, and prisms, respectively, at different ages (7, 28, and 56 days). The specimens were also heated up to 800 °C to evaluate the resistance of specimens to elevated temperature in terms of residual compressive strength and weight loss. The test results showed that the mechanical strength of GPC mixes (without steel fibers) increased by 6–11%, with an increase in QRD content up to 15% at the age of 28 days. In contrast, more than 15% of QRD contents resulted in decreasing the mechanical strength properties. Incorporating steel fibers in a fraction of 0.75% by volume increased the compressive, tensile, and flexural strength of GPC mixes by 15%, 23%, and 34%, respectively. However, further addition of steel fibers at 1.5% by volume lowered the mechanical strength properties. The optimal mixture of QRD incorporated FA-SG-based GPC (QFS-GPC) was observed with 15% QRD and 0.75% steel fibers contents considering the performance in workability and mechanical properties. The results also showed that under elevated temperatures up to 800 °C, the weight loss of QFS-GPC specimens persistently increased with a consistent decrease in the residual compressive strength for increasing QRD content and temperature. Furthermore, the microstructure characterization of QRD blended GPC mixes were also carried out by performing scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS).


2019 ◽  
Vol 15 (1) ◽  
pp. 48-57 ◽  
Author(s):  
R. Saraswathy ◽  
Jijo James ◽  
P. Kasinatha Pandian ◽  
G. Sriram ◽  
J. K. Sundar ◽  
...  

AbstractThe present study involved the utilization of crushed glass as an auxiliary additive in the manufacture of cement stabilized fly ash (CSF) bricks. The bricks were made with 1:1 proportion of fly ash and sand stabilized with 20 % cement. Crushed glass was used as replacement for the fine aggregate in increments of 10 % up to 40 % wherein the sand was completely replaced with crushed glass. The various mix proportions were then moulded into bricks with the addition of water by hand moulding method of forming the bricks and sun dried followed by sprinkle curing over a period of 21 days. The bricks were then subjected to compressive strength, water absorption and efflorescence tests to gauge its performance. The investigation revealed that the addition of crushed glass to the brick mix resulted in an increase in strength of the bricks, however, the maximum strength achieved could not achieve the strength of the control specimen. But the strength was higher than the minimum strength recommended by Bureau of Indian Standards (BIS) for stabilized blocks as well as burnt bricks. It also reduced the water absorption marginally while no efflorescence was seen in any of the combinations. A cost comparison revealed that the optimal combination with crushed glass was able reduce the cost of the brick by 20 %.


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