Development of Heavyweight Anti-Washout Self-Compacting Concrete Using Heavyweight Fine Aggregates Including Copper Slag

Effect of copper slag as a fine aggregate on the properties of cement mortars and concrete

The work reported in this paper is based on a laboratory study carried out to investigate the feasibility of using copper slag, a by-product of copper refineries, as a partial replacement of sand in the preparation of pavement quality concrete (PQC) and dry lean concrete (DLC) mixes. A control mix for PQC was prepared with 400 kg/m3 of ordinary Portland cement (OPC) and water–cement (w–c) ratio of 0.40. Other concrete mixtures were then prepared by substituting 20%, 40%, 60%, 80% and 100% copper slag in control mix. Workability and bleeding of green concrete, compressive strength, flexural strength at 7 and 28 days, drying shrinkage and abrasion resistance were measured for all the concrete mixtures. DLC mixtures were designed with 150 kg/m3 of OPC and different blends of stone dust with 20%, 40%, 60% and 80% copper slag as fine aggregate. DLC mixes were then prepared with different water contents with a view to find out the optimum water content for achieving maximum density, and corresponding compressive strength at 7 and 28 days for each blend of stone dust and copper slag. The laboratory test results showed that the compressive strength of PQC 7 and 28 days was not affected by inclusion of any content of copper slag as fine aggregate in the concrete mixture. Small gradual increase in flexural strength at 28 days was observed with an increase in copper slag content. Drying shrinkage of PQC decreased with the increase in slag and the decrease in stone dust content. Abrasion resistance of concrete mixes containing slag was observed to be less as compared with that of non-slag concrete. Compressive strength of DLC decreased with the increase in copper slag content beyond 40%. Keeping in view the strength and other important requirement of PQC such as cohesiveness, segregation, finishing, texturing, shrinkage and abrasion resistance, it was concluded that a blend of stone dust with copper slag content up to 40% could be used as fine aggregate for PQC as well as DLC.

Durability assessment of self compacting concrete incorporating copper slag as fine aggregates

Performance of high strength concrete made with copper slag as a fine aggregate

Sulfate resistance of self compacting concrete incorporating copper slag as fine aggregates with mineral admixtures

Self-Compacting Concrete has gained wide use for placement in congested reinforced concrete structures with difficult casting conditions while in Self Curing Concrete, water is restricted by means of some chemical compounds to move out from the concrete body. The main problem due to acute shortage and high price of river sand led to the enormous usage of M sand in construction. Use of copper slag as a fine aggregate is a good alternative to M sand and a better remedy to the disposal of copper slag. This investigation is aimed at utilizing the benefits of both self-compacting and self-curing concrete incorporating Copper Slag. In this study, the fresh and hardened properties of M50 equivalent Self-Compacting Concrete is obtained by incorporating 15% of Fly Ash as constant. Self-curing agent Polyethylene Glycol is added in 0, 0.5,1 and 1.5% to Self-compacting Concrete and its optimum is evaluated based on strength parameters. The optimum dosage of Copper Slag by the replacement of fine aggregate in different percentages of 10, 20, 30, 40 and 50% in Self-Compacting Self-Curing Concrete is obtained and their strength parameters are compared with normal Self Compacting Self-Curing Concrete. The utilization Fly Ash and Copper Slag which indirectly facilitate waste reduction helps in maintaining the ecological balance thus reduces the consumption of cement and aggregates.

Now-a-days, researchers are endeavoring to discover new substitute materials to elucidate the scarcity of natural aggregates in the construction industry. One such alternative is copper slag (CS) obtained as byproduct during the matte smelting process of copper metal. The present investigation is aimed to assess the durability of self compacting concrete (SCC) incorporating copper slag (CS) as fine aggregates and metakaolin (MK) as substitute to fly ash (FA). A total of seven concrete mixes were prepared. The control concrete contains 60% ordinary portland cement (OPC), 40% FA and 0% CS whereas other six mixes contains constant percentage of 60% OPC, 30% FA, 10% MK with different proportions of CS from 0% to 100%. Results revealed that fresh properties declined with inclusion of MK although escalated with increment of CS content. All SCC mixes exhibited higher compressive and splitting tensile strength in comparison to control concrete. The minimum carbonation depth was marked for 100% CS substitution with 10% MK as replacement to FA. The maximum electrical resistivity and resistance to sulfate attack were obtained for 20% CS substitution while UPV values of whole mixes were under the excellent quality of concrete beyond 7 days of curing. On full replacement of sand by CS with 10% MK, initial surface absorption and sorptivity were significantly lower than control concrete at each curing period. This study suggests that CS together with MK can be a potential substitute to natural sand in the construction sector to overcome the scarcity.

Self Compacting Concrete is a unique concrete, which allows compaction itself without any vibration by its gravity. Workability is the crucial factor for Self Compacting Concrete (SCC). It is also termed as fresh properties while considering SCC. Fresh properties include flowing ability, filling ability, segregation resistance, and passing ability. These can be measured by Slump flow, U-Box, V-Funnel, and L-Box ratio tests. Fly ash is partially replaced with cement at 5%, 10%, 15%, 20%, 25%, and 30%. Copper slag as a mineral admixture substituted in fine aggregate at the levels of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%. It was observed that the increase of fly ash and copper slag shows the improvement in the fresh properties. 20% fly ash used as optimum to replace copper slag in fine aggregate. 40% of copper slag has high mechanical properties than the regular mix.

Aggregate consumption rates have now exceeded natural renewal rates, signaling shortages both locally and globally. Even more concerning is that the worldwide markets for construction aggregates are projected to grow at an annual rate of 5.2% in the near future. This increase is attributed to rapid population growth coupled with the economic development worldwide. In terms of material availability, one of the most vulnerable regions is the Asia‐Pacific region specifically, Singapore, where there is higher demand but limited availability of natural sand and gravel for use as aggregates in concrete construction projects. This paper focuses mainly on the environmental impacts of fine aggregate alternatives used in high‐strength concrete applications in Singapore, which is one of the major global importers of natural sand following China. Singapore has been experiencing political and environmental challenges linked to the shortage of natural sand use as aggregates, even while the demand is increasing in the construction sector. Copper slag, a readily available waste material from shipyards in Singapore, is a possible replacement material for a portion of the natural sand in concrete mixtures, thus sustaining the projected growth in the region. A life‐cycle assessment approach is applied to investigate the environmental impacts of copper slag and its alternative use as natural sand in high‐strength concrete applications in Singapore. The system boundary consists of the major production processes of concrete constituents (including Portland cement and fine and coarse aggregates, with CS considered as fine aggregate) from a cradle‐to‐gate perspective, consisting of relevant life‐cycle phases of raw materials extraction, transportation, and production processes at the relevant facility where the production occurs. Output from the assessment is provided in terms of embodied energy use and air emissions of concrete mixes with varying percentages of copper slag as fine aggregate. Results show that environmental impacts of aggregates decrease with the increasing substitution rate of natural sand with copper slag when calculated on the basis per unit volume of the concrete mix. For example, 40% and 100% sand replacements with copper slag result in a reduction of 8% and 40% in embodied energy, 12% and 30% in global warming potential, 8% and 41% in acidification, and 7% and 35% in particulate matter formation, respectively. Normalized impacts (i.e., normalized with respect to compressive strength) are observed to remain at almost similar levels for concrete mixes with up to 40% natural sand having been replaced with copper slag. Therefore, it is recommended that replacement of fine aggregates by 40–50% of copper slag (by weight) will produce concrete mixtures with comparable environmental impacts while maintaining feasible durability and strength properties.

This paper represents experimental work on the mechanical and durability parameters of self-compacting concrete (SCC) with copper slag (CS) and fly ash (FA). In the first phase of the experiment, certain SCC mixes are prepared with six percentages of FA replacing the cement ranging from 5% to 30%. In the second phase, copper slag replaces fine aggregate at an interval of 20% to 100% by taking the optimum percentage value of FA. The performance of SCC mixes containing FA and copper slag is measured with fresh properties, compressive, split tensile and flexural strengths. SCC durability metrics, such as resistance against chloride and voids in the concrete matrix, is measured with rapid chloride ion penetration test (RCPT) and sorptivity techniques. The microstructure of the SCC is analyzed by using SEM and various phases available in the concrete matrix identified with XRD analysis. It is found that when replacing cement with 20% of FA and replacing fine aggregate with 40% of copper slag in SCC, higher mechanical strengths will be delivered. Resistance of chloride and voids in the concrete matrix reaches the optimum value at 40%; and with the increase of dosage, the quality of SCC will be improved. Therefore, it is recommended that copper slag be used as a sustainable material for replacement of fine aggregate.

Over the years, the construction industry is highly dependent on concrete for meeting the global demand of building new infrastructure. Various advancements in normal concrete have been made to make the concrete industry more efficient and developed. High strength concrete (HSC), and self-compacting concrete (SCC) are two revolutionary developments in the concrete industry that have increased the dependency of the world on concrete due to their enhanced mechanical and durability properties. However, CO2 emissions associated with cement and concrete manufacturing have created an alarming situation, and as the world is looking for sustainability and cleaner production, the pressure on the concrete industry to minimize the use of natural aggregates and cement is also increasing. Geopolymer concrete (GPC) is a type of concrete that uses various industrial wastes as a binder instead of cement and these by-products are activated by alkali. GPC is still under research and yet to be developed as a reliable product, however, the available research validates the lesser environmental impacts in GPC as compared to cement-based concrete. Other efforts have also been made to reduce the environmental impacts in concrete and substitution of natural fine aggregate (NFA) with industrial by-products is one such step that not only provides an efficient method of waste disposal but also reduces the dependency of concrete on natural resources. Copper slag (CS) is a type of nontoxic industrial waste that is obtained during matte smelting and refining of copper. CS resembles the size of NFA and can be used as partial or full replacement of NFA in various types of concrete. Various researchers have investigated the potential use of CS as NFA replacement in conventional concrete, HSC, SCC, and GPC. The current study summarizes the up-to-date trends as reported in available literature wherein CS has been used as fine aggregate in conventional concrete, HSC, SCC, and GPC. Present investigations support the use of CS as a fine aggregate in concrete. Apart from the key findings, various identified gaps, challenges, and future scope challenges have also been discussed to develop CS as a sustainable material in the construction industry.

Studies on ultra high performance concrete incorporating copper slag as fine aggregate

Strength characteristics of concrete made with copper slag and fly-ash

Sustainable construction materials are those which contributes towards the carbon- negative process of manufacturing. Cement produced by raw materials from industrial wastes and non-fossil fuel sources is considered as green cement which has high potential in constructions due to high tensile strength and resistance to corrosion. Exploring replacement materials for conventional cement is an active area of research. This data investigation focused on development of novel concrete mix with various proportions of sustainable supplementary materials with cement, fine and coarse aggregate substances. Alccofine, Metakaolin, GGBFS, Foundry sand, Copper slag, Recycled aggregate and Sintered fly ash aggregate are suitable supplementary materials of the concrete mix. Data projected replacement of cement by 15 % Alccofine, 10% Metakaolin and 30% GGBFS substitution and Fine aggregates (50% Copper slag, 30% Foundry sand) and replacement of Coarse aggregate (20% Recycled and 30% Sintered Fly Ash aggregate) will produce sustainable concrete mixture. Compressive and split tensile strength examined at 7th, 14th and 28th day and compared with conventional concrete. This data shows that the concrete mixture CFACA 1234567 was outperformed among the five mixture studied.

The ever-increasing cost of natural sand and the environmental impacts of extracting manufactured sand (quarry sand) calls for exploring the potential to use alternative materials as fine aggregates in concrete. Copper slag and ferrous slag are industrial by products obtained from the smelting process of copper and iron respectively. A large quantity of copper slag and ferrous slag end up being disposed as waste in landfills and this poses a serious threat to the environment. Copper slag and ferrous slag have similar physical and chemical properties as natural sand and also exhibit pozzolanic activity. This paper studies the technical feasibility of industrial by-products such as copper slag and ferrous slag to replace the fine aggregate in concrete by evaluating the workability, strength and durability characteristics of concrete. The test results indicate that the strength properties are not affected by 40% or 100% replacement of quarry sand with iron slag or copper slag. However, 40% replacement of quarry sand with iron slag or copper slag in concrete is recommended considering the durability aspects of concrete.