Effects of Water Cement Ratio on Strengths Characteristics of Concrete Produced with Recycled Iron and Steel Slag (RISS) Aggregate

2021 ◽  
Vol 107 ◽  
pp. 97-112
Author(s):  
Akeem Ayinde Raheem ◽  
Oluwaleke A. Olowu ◽  
Anthony Ajibola Hungbo ◽  
Emmanuel Olatunde Ibiwoye
Keyword(s):  
Structural Integrity ◽  
Silicon Oxide ◽  
Steel Slag ◽  
Mineralogical Composition ◽  
Iron And Steel ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
The Common ◽  
Compressive And Flexural Strengths

Effects of Water cement ratios on strengths characteristics of concrete produced with Recycled Iron and Steel Slag (RISS) aggregates was studied to understand the structural integrity of RISS aggregate in concrete and to determine the veracity of RISS aggregate as alternative aggregate to granite in concrete works. Mineralogical composition of the aggregate showed Silicon oxide (quartz) as the common mineral; both aggregates are well graded, strong and durable. Lower water cement ratios improved both the compressive and flexural strengths of RISS and granite concrete.

scholarly journals Enhancing the Flexural Strength of Concrete using Recycled Iron and Steel Slag Aggregate

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. A Raheem
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Concrete Beams ◽  
Steel Slag ◽  
Aggregate Size ◽  
Mineralogical Composition ◽  
Maximum Aggregate Size ◽  
Considerable Effort ◽  
Iron And Steel ◽  
Coefficient Of Uniformity

Concrete is strong in compression but weak in tension hence, considerable effort is required to improve concrete’s tensile strength by the use of pre-stressed concrete and addition of admixtures or additives. In this study, the use of recycled iron and steel slag (RISS) aggregate to improve the tensile strength of concrete was considered. The paper assessed the mineralogical composition of RISS and granite aggregates, and gradation. It also determines the effects of RISS aggregate on the flexural strength of concrete beams of 150 × 150 × 600 mm containing 0, 10, 20, 40 and 60% RISS aggregate replacement in mix ratios 1:1½:3, 1:2:4 and 1:3:6 with water cement ratios 0.65,0.60 and 0.55 respectively. Diffractograph of RISS and granite aggregate showed that RISS contains Magnetite, Ilmenite and Quartz, while granite contains Quartz, Annite, Microcline and Albite as the predominant minerals. The coefficient of uniformity and concavity of RISS and granite aggregate for maximum aggregate size of 37.5 mm are 4.35 and 1.33; and 4.64 and 1.76 respectively. Both aggregates contain quartz as the predominant mineral and are well graded. The result of the Flexural strength at 28 days curing is within 0.135 – 0.250 MPa specified byBS8500 – 2:2015. Flexural strength of concrete beams cast with RISS aggregate is relatively higher than concrete cast with granite aggregate. Flexural strength, a measure of tensile strength of concrete is improved as percentage RISS aggregate increased.

PERFORMANCE OF STEEL SLAG AGGREGATE CONCRETE WITH VARIED WATER- CEMENT RATIO

2016 ◽  
Vol 78 (10) ◽  
Author(s):  
Paul O. Awoyera ◽  
Olurotimi M. Olofinnade ◽  
Ayobami A. Busari ◽  
Isaac I. Akinwumi ◽  
Moyosore Oyefesobi ◽  
...  
Keyword(s):  
Steel Slag ◽  
High Strength ◽  
Tensile Tests ◽  
Normal Weight ◽  
Hardened Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Normal Weight Concrete ◽  
Technical Details ◽  
Electric Arc Furnace Slag

Several thousands of tons of electric arc furnace slag (EAF) slag generated in Nigeria are yet to be utilised for construction; perhaps as a result of inadequate technical details for its use. The present study has evaluated the effects of varying water-cement ratio on workability and strength of locally generated steel slag aggregate (SSA) concrete. Tested samples include 150 mm concrete cubes and cylinder samples with 150 mm diameter and 300 mm height respectively. SSA was substituted in increments of 20% by weight of granite until 100% mix, while w/c was varied at 0.5, 0.55 and 0.6. Workability of fresh concrete was evaluated through slump test. Hardened concrete cubes and cylinders were subjected to compression and split tensile tests respectively, after 7, 14 and 28 days curing periods. Slump values obtained were in the range of 50 – 90 mm for all the mixes, which represented a S2 slump. Compressive strength and tensile strength increased with age and increasing slag substitution. A strength of 25 MPa for normal weight concrete was achieved at 28 days with 20% SSA substitution, only within 0.5 and 0.55 w/c ratio. However, result obtained for concrete mixes with 60% SSA and above at 28 days established that these mixes are good for production of high strength concrete.

scholarly journals Bacteria incorporated with calcium lactate pentahydrate to improve the mortar properties and self-healing occurrence

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Siti Khodijah Chaerun ◽  
Ridwan Syarif ◽  
Ridho Kresna Wattimena
Keyword(s):  
Organic Carbon ◽  
Physical Properties ◽  
Mineralogical Composition ◽  
High Energy ◽  
Calcium Lactate ◽  
Self Healing ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Micro Cracks ◽  
Bacterial Inoculum

Abstract Concrete can be harmful to the environment due to its high energy consumption and CO2 emission and also has a potential crack formation, which can promote a drop in its strength. Therefore, concrete is considered as a non-sustainable material. The mechanisms by which bacterial oxidation of organic carbon can precipitate calcite that may fill the voids and cracks on cement-based materials have been extensively investigated to prevent and heal the micro-cracks formation. Hence, this study focused on utilizing a new alkaliphilic bacterial strain indigenous to an Indonesian site, Lysinibacillus sphaericus strain SKC/VA-1, incorporated with calcium lactate pentahydrate, as a low-cost calcium source, with various bacterial inoculum concentrations. The bacterium was employed in this study due to its ability to adapt to basic pH, thus improving the physical properties and rejuvenating the micro-cracks. Experimentally, the addition of calcium lactate pentahydrate slightly affected the mortar properties. Likewise, bacteria-incorporated mortar exhibited an enhancement in the physical properties of mortar. The highest improvement of mechanical properties (an increase of 45% and 36% for compressive and indirect tensile strength, respectively) was achieved by the addition of calcium lactate pentahydrate incorporated with 10% v/v bacterial inoculum [about 7 × 107 CFU/ml (colony-forming unit/ml)]. The self-healing took place more rapidly on bacterial mortar supplemented with calcium lactate pentahydrate than on the control specimen. XRD analysis demonstrated that the mineralogical composition of self-healing precipitates was primarily dominated by calcite (CaCO3), indicating the capacity of L. sphaericus strain SKC/VA-1 to precipitate calcite through organic carbon oxidation for self-healing the artificial crack on the mortar. To our knowledge, this is the first report on the potential utilization of the bacterium L. sphaericus incorporated with calcium lactate pentahydrate to increase the mortar properties, including its self-healing ability. However, further study with the water-cement ratio variation is required to investigate the possibility of using L. sphaericus and calcium lactate pentahydrate as an alternative method rather than reducing the water-cement ratio to enhance the mortar properties.

scholarly journals Long Term Compression Strength of Mortars Produced Using Coarse Steel Slag as Aggregate

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Erika Furlani ◽  
Stefano Maschio
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Compression Strength ◽  
Steel Slag ◽  
Alkali Silica Reaction ◽  
Steelmaking Slag ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Long Time

The paper reports on some experimental results obtained from the production of mortars prepared using a commercial cement, coarse steelmaking slag, superplasticizer, and water. The behaviour of this reference composition was compared to that of some others containing further additives in order to investigate materials compressive strength after long time ageing. It has been demonstrated that an optimized water/cement ratio coupled with slag particles of size lower than 2.5 mm and proper protocol of preparation leads to the production of materials with good mechanical properties after 28, 90, and 180 days of ageing. The resulting materials therefore appeared as good candidates for civil engineering applications. However, the present research also demonstrates that the mortar samples of all of the compositions prepared suffer from decay and compressive strength decrease after long time ageing in water. In the present paper the results are explained taking account of materials residual porosity and alkali silica reaction which occurs in the samples.

Experimental Study on Activity of Fly Ash Replacing Cement in Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 46-49
Author(s):  
Chang Yong Li ◽  
Long Jiang ◽  
Yang Liu ◽  
Zhi Ming Xu
Keyword(s):  
Experimental Study ◽  
Fly Ash ◽  
Cement Ratio ◽  
Active Factor ◽  
Water Cement Ratio ◽  
Binder Ratio ◽  
Mass Factor ◽  
Compressive And Flexural Strengths ◽  
Water Binder Ratio

The test and contrast mortars were made by changing water-binder (water-cement) ratio from 0.4 to 0.6, fly ash replacing rate from 10% to 30% and over-mass factor of fly ash from 1.3 to 1.7 with different methods of equal-replacing and over-mass replacing cement by fly ash. The variation of compressive and flexural strengths of mortar with water-binder ratio and admixing amount of fly ash are analyzed based on the test strengths. The formulas for calculating active factor of fly ash are proposed, and the regularity of active factor with the change of water-binder ratio and admixing amount of fly ash are given out.

scholarly journals Numerical Simulation of Basic Properties of Full-Steel Slag Aggregate Concrete

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Zhu Bian ◽  
Yuan Fang ◽  
Feng Yu ◽  
Xuliang Wang ◽  
Guosheng Xiang
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Steel Slag ◽  
Back Propagation ◽  
Expansion Rate ◽  
Aggregate Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Basic Properties ◽  
Neural Network Prediction

In this study, the bit-level table of orthogonal test is adopted as the coding form of Genetic Algorithm (GA), and a Back Propagation (BP) neural network prediction model of the basic properties of full steel slag aggregate concrete (FSSAC) is established, and the experiment data are validated with good agreement. The impacts of several parameters including the sand ratio, water-cement ratio, content of steel slag sand, replacement particle size of steel slag sand, content of coarse steel slag, and replacement particle size of coarse steel slag on the compressive strength and expansion rate of the FSSAC are numerically investigated. The results show that the compressive strength of the FSSAC declines with the increase of the sand ratio, water-cement ratio, content of the steel slag sand, or coarse steel slag while it first increases and then decreases as the replacement particle size of steel slag sand or replacement particle size of coarse steel slag increases. The expansion rate of the FSSAC increases as the sand ratio or content of coarse steel slag increases. With a gradual increase of the water-cement ratio, content of steel slag sand, replacement particle size of steel slag sand, or replacement particle size of coarse steel slag, the expansion rate of the FSSAC first increases and then decreases. In addition, the impacts of the three most important parameters (i.e., water-cement ratio, content of steel slag sand, and replacement particle size of steel slag sand) on the stress-strain relationship of the FSSAC stub columns is further numerically studied.

scholarly journals Effectiveness of Locally Available Superplasticizers on the Workability and Strength of Concrete

2018 ◽  
Vol 4 (12) ◽  
pp. 2919 ◽  
Author(s):  
Ashfaque Ahmed Jhatial ◽  
Samiullah Sohu ◽  
Muhammad Tahir Lakhiar ◽  
Jam Shahzaib ◽  
Ahsan Ali Buriro
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Water Content ◽  
Research Work ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Optimum Dosage ◽  
Chemical Admixtures ◽  
Compressive And Flexural Strengths

Though superplasticizers (SP) are well-known chemical admixtures which are added into concrete to enhance the workability and achieve higher strength while reducing the water content. But the rapid increase in different SP in Pakistan has created confusion on the effectiveness of SP. This experimental study was carried out to study the effect of locally available SP on the workability and compressive strength of M15 grade concrete. Three different SP were utilized, with dosage ranging from 0.5% to 2.5% with an increment of 0.5%. The water-cement ratio remained constant at 0.5 for all samples. Based upon the results, all three SP increased the workability as well as strength of concrete. The optimum dosage was determined to be 1.5% to 2.00% for all three SPs used in this research work. BASF 561 was determined to be more effective, as it achieved the maximum workability as well as compressive and flexural strengths.

Strength Indicators Of Cement Systems With Additives Of Surface - Active Substances

2021 ◽  
Vol 03 (05) ◽  
pp. 203-209
Author(s):  
Teshaboeva Nodira Djuraevna ◽  
Keyword(s):  
Mineralogical Composition ◽  
Strength Characteristics ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Surface Active ◽  
Active Substances ◽  
Control Samples

In the article, the study was to establish the effect of surfactant additives on the strength characteristics of cement systems. The determinations were carried out on cements of various mineralogical composition, freshly ground and stale, on cement-sand mortars and concretes. For control samples and with additives, the same plasticity was chosen, and the water-cement ratio than for various additives fluctuated within certain limits.

Research on the Strength of High-Strength Steel Slag Concrete with Skeleton Coarse Aggregate Gradation

2013 ◽  
Vol 671-674 ◽  
pp. 1918-1922
Author(s):  
Yi Zhou Zhuang ◽  
Er Bu Tian ◽  
Yue Zong Lian
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
Concrete Strength ◽  
Steel Slag ◽  
High Strength ◽  
Test Results ◽  
Aggregate Gradation ◽  
Cement Ratio ◽  
Water Cement Ratio

Generally the high density in high-strength concrete results in high strength, and so people often mix superplasticizer and particulate to increase the density of concrete, but ignoring the effect of coarse aggregate gradation on concrete strength. Referring to several Gradation Theories, this paper selects the coarse aggregate gradation with skeleton, uses uniform design method to test the compressive strength of high-strength concrete, and analyses the test results. It can be known from the test results of 7d and 28d concrete specimen that the concrete strength decreases linearly with water-cement ratio and sand ratio; The 7d’s concrete strength has higher variability due to low water-cement ratio with superplasticizer; The coarse aggregate skeleton is interfered by the increase of steel slag and sand rate, and the concrete strength decreases with limited cement paste. Furthermore, the steel slag with less than 30% addition has little effect on concrete strength and it can increase the cement’s possibility of contacting to water, and reduce the amount of cement without lowering the concrete strength. The influential degree on the compressive strength of concrete is followed by ascending sequence of steel slag content, sand ratio and water-cement.

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