scholarly journals Assessment of the optimal level of basalt pozzolana blended cement replacement against concrete performance

2021 ◽  
Vol 68 (1) ◽  
Author(s):  
Mohamed S. Moawad ◽  
Shimaa Younis ◽  
Abd EL- Rahman Ragab

AbstractDifferent additional cementitious materials can be used to partially replace cement in concrete. these are used in concrete as a partial replacement for cement to reduce the effect of environmental pollution, which can lead to serious health issues. Therefore, it is critical to use locally available pozzolanic materials as a partially replacement for cement because these materials are less expensive than Portland cement and are more environmentally friendly without sacrificing concrete quality. Pozzolana made from basalt natural material was tested for the best amount of weight percentage replacement as a blinding component in cements in this study. Various percentage of basalt as a partial replacement weight percentage of ordinary Portland cement by 7.5%, 15%, and 22.5% is carried out. effect of basalt on workability, setting time, compressive strength, modulus of elasticity, tensile strength, flexural strength, and water absorption were conducted. The parameters were studied and monitored by tested a fresh and hardened concrete samples at ages of 7 days, 28 days, 56 days, and 90 days. Based on the test results, it is concluded that the optimal content of basalt as replacement of ordinary Portland cement in concrete mix is 15%.

Author(s):  
Safiki Ainomugisha ◽  
Bisaso Edwin ◽  
Bazairwe Annet

Concrete has been the world’s most consumed construction material, with over 10 billion tons of concrete annually. This is mainly due to its excellent mechanical and durability properties plus high mouldability. However, one of its major constituents; Ordinary Portland Cement is reported to be expensive and unaffordable by most low-income earners. Its production contributes about 5%–8% of global CO2 greenhouse emissions. This is most likely to increase exponentially with the demand of Ordinary Portland Cement estimated to rise by 200%, reaching 6000 million tons/year by 2050.  Therefore, different countries are aiming at finding alternative sustainable construction materials that are more affordable and offer greener options reducing reliance on non-renewable sources. Therefore, this study aimed at assessing the possibility of utilizing sugarcane bagasse ash from co-generation in sugar factories as supplementary material in concrete. Physical and chemical properties of this sugarcane bagasse ash were obtained plus physical and mechanical properties of fresh and hardened concrete made with partial replacement of Ordinary Portland Cement. Cost-benefit analysis of concrete was also assessed. The study was carried using 63 concrete cubes of size 150cm3 with water absorption studied as per BS 1881-122; slump test to BS 1881-102; and compressive strength and density of concrete according to BS 1881-116. The cement binder was replaced with sugarcane bagasse ash 0%, 5%, 10%, 15%, 20%, 25% and 30% by proportion of weight. Results showed the bulk density of sugarcane bagasse ash at 474.33kg/m3, the specific gravity of 1.81, and 65% of bagasse ash has a particle size of less than 0.28mm. Chemically, sugarcane bagasse ash contained SiO2, Fe2O3, and Al2O3 at 63.59%, 3.39%, and 5.66% respectively. A 10% replacement of cement gave optimum compressive strength of 26.17MPa. This 10% replacement demonstrated a cost saving of 5.65% compared with conventional concrete. 


2015 ◽  
Vol 9 (1) ◽  
pp. 180-186
Author(s):  
Kae-Long Lin ◽  
Chao-Lung Hwang ◽  
Yu-Min Chang

The aim of this study is to investigate the pozzolanic characteristics of circulating fluidized bed fly ash blended cement (CFBFABC) paste containing circulating fluidized bed fly ash (CFBFA). The initial and final setting time of CFBFABC pastes with CFBFA retards with an increasing CFBFA content. CFBFABC pastes containing 10% CFBFA exhibited a compressive strength similar to that of ordinary Portland cement pastes at the ages of 90 days. X-ray diffraction peaks indicated the presence of portlandite, ettringite, and unreacted C3S (32.6°) and C2 (41.9°). The gel/space ratio of the CFBFABC pastes increased with the curing time and decreased as the CFBFA content increased. The gel/space ratio increased with the curing time because of the progress of hydration, which led to some of the pores being filled. At the ages of 90 days, the gel/space ratio of the CFBFABC pastes containing 10% CFBFA increased to approximately 14%, it is possibly the consumption of Ca(OH)2 and the formation of C-S-H in the CFBFABC pastes. The CFBFABC pastes containing 10% CFBFA did not exhibit any major decrease in the gel/space ratio. It exhibited favorable mechanical characteristics that were observed when the mixing ratio of CFBFA was 10%. Furthermore, CFBFA has the potential, as a pozzolanic material, partially to replace ordinary Portland cement.


Author(s):  
L. S. Gwarah ◽  
B. M. Akatah ◽  
I. Onungwe ◽  
P. P. Akpan

The investigation of sawdust ash (SDA) as a partial replacement for cement in concrete was studied owing to the high cost and increasing demand for cement in a harsh economy and considering the presence of limited construction materials and waste to wealth policy. Ordinary Portland Cement (OPC) was replaced by 0%, 5%, 10%, 15%, 20%, 25% and 30% of SDA. Slump test and consistency test (flow table apparatus test) were conducted on the freshly mixed concrete sample, and compressive strength test was conducted on the hardened concrete cubes of 150mm2, which was cured between 7, 14, 21 and 28 days. The results revealed that the slump decreases as the SDA content increases in percentage, while the consistency of the freshly mixed concrete remarkably moves from high, medium to low as the SDA content increases. The compressive strength of the hardened concrete undergone a decrease in strength, as the partial replacement of OPC with SDA increases. By the results interpretation, it is observed that 5% to 10% SDA when replaced with OPC can still result in the desired strength of concrete.


Author(s):  
Panditharadhya B J

Aluminium dross is generated when resmelting process is done in an aluminium industry to recover residual aluminium, wherein primary dross is taken as a raw material. It is completely a waste product and hazardous to dispose it into landfills. This is rich in aluminium oxide and having traces of few heavy metals. It is necessary to check the eco-friendly methods of solidification of this material. One of the feasible methods of solidifying the industrial wastes is using them in production of cement concrete. In this study, behaviour of aluminium dross as a partial replacement for Ordinary Portland Cement is evaluated. Aluminium dross is replaced at 5, 10, 15 and 20% of Ordinary Portland Cement. Consistency and setting time of cement paste samples were determined which shows a lag in setting time of paste. Workability and setting time of concrete mixes with 5, 10, 15 and 20% of Aluminium dross as a binder, were evaluated. Retardation of setting time and increase in the workability are the main observations of this study. As the percentage of aluminium dross increases, the setting time also increases. This may be considered as a reason to utilize such concrete mixes in hot weather conditions wherein delayed setting time is an added advantage. Therefore, retardation of setting time is the positive impact of aluminium dross. Keeping in view of the fact that there can be a reduction in strength with increased binder replacement and the workability requirements, only up to 20% of aluminium dross was replaced in the present study.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1609
Author(s):  
Rohollah Rostami ◽  
Agnieszka J. Klemm ◽  
Fernando C. R. Almeida

Supplementary cementitious materials (SCMs), such as fly ash (FA) and ground granulated blast-furnace slag (GGBS), are often used as a partial replacement of cements to improve the sustainability of Portland cement-based materials and reduce their environmental impact. Superabsorbent polymers (SAPs) can be successfully used as internal curing agents in ultra-high performance cementitious materials by facilitating the hydration process and controlling the water supply in both fresh and hardened states. This paper intends to characterise the physical and chemical properties of SAPs and their sorption properties in different blended cement environments. The swelling capacity and kinetics of absorption of three superabsorbent polymers with different chemical compositions and grading were tested in different cement environments. Experimental results of their sorption performance in distinct solutions, including deionised water (DI), Portland cement (PC), and blended cements (PC-FA and PC-GGBS) and changes in pH of different solutions over time were investigated. The results showed that PC-FA solution had the lowest pH followed by PC-GGBS solution. Moreover, SAPs samples displayed the highest absorption capacities in PC-FA solutions, and the lowest swelling capacities were found in PC-GGBS solutions. Furthermore, SAP with smaller particle sizes had the greatest absorption capacity values in all solutions.


2016 ◽  
Vol 7 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Neelu Das ◽  
Shashikant Singh

 In this paper, the potential use of water hyacinth stem ash (WHA) in the partial replacement of cement is studied. WHA was used as a replacement for ordinary Portland cement at 10, 15, 20 and 25 wt. %. To evaluate the pozzolanic activity of WHA, the properties investigated were chemical composition, particle size, soundness, setting time, specific gravity, presence of crystalline matter, compressive strength, water absorption and sorption. Mortar cubes were tested for compressive strength up to the age of 56 days, whereas water absorption and sorption tests are carried out at the age of 28 days. Test results reveal that mortar cubes with 10% WHA substitution for Portland cement produced comparative compressive strength values to control mortar. It was also observed that the use of WHA in Portland cement has reduced water absorption characteristics.


2019 ◽  
Author(s):  
Mala Babagana Gutti ◽  
Ani Abdulfatah Musa

The use of waste materials with pozzolanic products in concrete production is becoming a worldwide practice. The assessment of the pozzolanic activity of cement replacement materials is becoming increasingly important because of the need for more sustainable cementing products. In this report, black currant leaf ash is used as partial replacement of 5% of the concrete material. The Strength and durability test were carried out in order to assess the feasibility of using black currant leaf ash as partial replacement of cement in concrete. A total of 18 concrete cubes of 150mm x 150mm x 150mm in size were produced with ordinary Portland cement, 9 concrete cubes as control mix and 9 concrete cubes of black currant blended cement concrete, the samples were tested, weighed, and crushed to obtain their compressive strength after curing in water at age 7, 14 and 21 days. The after the study was completed it was found that the strength of the concrete increase as the samples with replacement were almost the same in strength as the control, Therefore, ordinary Portland cement-black currant blended cement concrete could be used in civil engineering and building works, especially where early strength is not a major requirement, thereby reducing the cost of production.


Author(s):  
Agboola Shamsudeen Abdulazeez ◽  
Amina Omolola Suleiman ◽  
Simdima Gabriel Gideon ◽  
Solomon Wutong Poki

- Presently researches all over the world is concentrating on alternative materials as partial cement replacement in concrete production. The use of pozzolanic material in concrete is becoming increasingly important because of the need for more sustainable cementing products. Volcanic ash is a form of natural pozzolan and has a chemical composition comparable to other supplementary cementitious materials. In this paper, volcanic ash was used to partially replace cement in the ratio of 0%, 5%, 10%, 15% and 20% by volume in concrete and cured in H2SO4 and MgSO4 environment. 28-day target strength was adopted and concrete tested at 7, 14, 28 and 56 days’ hydration period. Specific gravity, bulk density and setting time test on volcanic ash were carried out. Fresh concrete tests such as slump and compacting factor test were carried out along-side hardened concrete tests like compressive strength and split tensile strength. The result shows that the maximum compressive strength at 28 days was at 0% control concrete, while at 56 days the maximum strength was observed at 10% replacement of cement with volcanic ash and it is considered as optimum percentage replacement.


In this research work, the effect of rice husk ash on concrete produced with cellulose industrial residue was studied. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of Ordinary Portland Cement (OPC) with cellulose industrial residue and rice husk ash used were 0%, 5%, 10%, 20% 30% and 40%. Concrete cubes of 150mm x 150mm x 150mm of Ordinary Portland Cement/Cellulose Industrial Residue and Ordinary Portland Cement/Cellulose Industrial Residue/Rice Ash were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the concrete cubes were crushed and their compressive strength were determined. The result of compressive strength of 5-40% replacement of cement with cellulose industrial residue ranges from 13.02-32.81 N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the compressive strength of 5-40% replacement of cement with Cellulose Industrial Residue and Rice Husk Ash ranges from 13.17-36.30N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the initial and final setting time of Ordinary Portland Cement/Cellulose Industrial Residue and Cement/Cellulose Industrial Residue/Rice Husk Ash for 5-40% replacement of cement ranges from 61-118mins, 58-110mins and 620 – 836mins, 598 – 799mins respectively as against 52mins and 590mins for the control test. The main conclusion of this study is that the incorporation rice husk ash into cellulose industrial residue increase the strength of concrete produced. The objective of this study is to assess the strength of concrete produced when two pozzolanic materials were used to replace cement in producing concrete.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3467
Author(s):  
Ankit Kothari ◽  
Karin Habermehl-Cwirzen ◽  
Hans Hedlund ◽  
Andrzej Cwirzen

Most of the currently used concretes are based on ordinary Portland cement (OPC) which results in a high carbon dioxide footprint and thus has a negative environmental impact. Replacing OPCs, partially or fully by ecological binders, i.e., supplementary cementitious materials (SCMs) or alternative binders, aims to decrease the carbon dioxide footprint. Both solutions introduced a number of technological problems, including their performance, when exposed to low, subfreezing temperatures during casting operations and the hardening stage. This review indicates that the present knowledge enables the production of OPC-based concretes at temperatures as low as −10 °C, without the need of any additional measures such as, e.g., heating. Conversely, composite cements containing SCMs or alkali-activated binders (AACs) showed mixed performances, ranging from inferior to superior in comparison with OPC. Most concretes based on composite cements require pre/post heat curing or only a short exposure to sub-zero temperatures. At the same time, certain alkali-activated systems performed very well even at −20 °C without the need for additional curing. Chemical admixtures developed for OPC do not always perform well in other binder systems. This review showed that there is only a limited knowledge on how chemical admixtures work in ecological concretes at low temperatures and how to accelerate the hydration rate of composite cements containing high amounts of SCMs or AACs, when these are cured at subfreezing temperatures.


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