Production Of Concrete Blocks Research Articles

Analysis of Waste in the Production of Concrete Blocks—A Case Study in the Goiás Industry

Analysis of Waste in the Production of Concrete Blocks—A Case Study in the Goiás Industry

Results of the Leaching, Water Absorption and Mold Release for Concrete Blocks with the Addition of the Concentration Tailings of Iron Ore

Tailings from the concentration of iron ore can be substituted in part for the production of concrete blocks due to the ability of encapsulation or enveloping the concrete. Many tests were conducted to recycle Concentration Tailings of Iron Ore for the Production of Concrete Block, replacing the silica sand. The Concentration Tailings of Iron Ore showed to be viable materials for the replacement of coarse and fine aggregate concrete blocks (pavers), with regard to mechanical strength after 28 days cure. Specifically, the simple substitution of hail for coarse tailings concentration of iron ore has the potential to increase the compression resistance of the concrete blocks. It was also verified that the addition of fine tailings with magnetic concentration may complicate demolding.The water absorption of the concrete block was obtained in accordance with the standards, and some blocks were within the required standards. And through the leaching test was observed that the addition of the tailings concrete blocks poses no risk to the environment when exposed to weather.

Use of Compactation Tests for Defining Process Mixtures Parameters to Concrete Blocks

In recent years, Brazil has been going through a period of economic growth and is now facing the acceleration of this development, the presence of engineering in all its areas, becomes crucial to sustain this condition. A primary form of this chain, the use of conforming materials, joins an entire production process which should result in works that have as their main focus the minimum quality of the finished product. For this reason, definition and understanding of aspects such as mixture and all parameters involved in the production of materials becomes critical. For concrete block, there is a series of steps that will culminate in a final product quality, always appropriate to the project while respecting normative aspects. Within these stages of production of concrete blocks, using the method of lower volume of voids, this paper will explore the definition of the best mixes of aggregate/coarse and the definition of the moisture content of the mixture and the correlation of compacted test specimens, with blocks produced using specific standards for soil cement NBR 12023/92 [ and 12024/92 [. In this study we observed that there is a correlation of 95.30% compressive strength of the compact tests specimens with the concrete blocks producing in vibro press. This correlation allows us to design a dosing process using a previous best volume of material due to the smaller size of CPs, streamlining and minimizing the costs of the definition of dosing parameters. In relation to the moisture content, it was noted that the value set in the compaction test must be adjusted when the blocks are made in the press, since energy of compaction is larger in that case. Thus for the production of the blocks, humidity value was 10.71% less than that defined by the compaction test.

Mechanical and toxicological evaluation of concrete artifacts containing waste foundry sand

The creation of metal parts via casting uses molds that are generally made from sand and phenolic resin. The waste generated after the casting process is called waste foundry sand (WFS). Depending on the mold composition and the casting process, WFS can contain substances that prevent its direct emission to the environment. In Brazil, this waste is classified according to the Standard ABNT NBR 10004:2004 as a waste Class II (Non-Inert). The recycling of this waste is limited because its characteristics change significantly after use. Although the use (or reuse) of this byproduct in civil construction is a technically feasible alternative, its effects must be evaluated, especially from mechanical and environmental points of view. Thus, the objective of this study is to investigate the effect of the use of WFS in the manufacture of cement artifacts, such as masonry blocks for walls, structural masonry blocks, and paving blocks. Blocks containing different concentrations of WFS (up to 75% by weight) were produced and evaluated using compressive strength tests (35MPa at 28days) and toxicity tests on Daphnia magna, Allium cepa (onion root), and Eisenia foetida (earthworm). The results showed that there was not a considerable reduction in the compressive strength, with values of 35±2MPa at 28days. The toxicity study with the material obtained from leaching did not significantly interfere with the development of D. magna and E. foetida, but the growth of the A. cepa species was reduced. The study showed that the use of this waste in the production of concrete blocks is feasible from both mechanical and environmental points of view.

English

Cellular concrete blocks are the major building materials in Kurdistan Region in Iraq. This study is carried out to check the economical and structural feasibility. The integrity of the blocks as well as its industrial production process compared with local and international standards. Recommendations for the concrete block production have been given in this paper. Samples from 10 local factories of total 60 blocks have been collected and tested at Koya University Laboratory. The carried out tests covered the dimensions, compression strength and water absorption of the samples. The results of this research study were compared with the requirements of the Iraqi and European specifications. They showed that the products of all factories do not fulfil the specified requirements. The dimensions of specimens exhibited relatively high deviations with no recommended tolerances for dimensions of the blocks. The results analysis showed that the weight of the 400x200x200mm block size was about 20-23 kg and the size of the represented voids was about 60% of the volume. This study made some regulatory recommendations to standardise the concrete block production in the region.

Production of Concrete Blocks with Residues for Civil Construction

The Construction is recognized as one of the most important activities for the economic and social development, and on the other hand, behaves also as a major generator of environmental impacts, either by consumption of natural resources, the modification of the landscape or the generation of construction and demolition waste (CDW). Investing in an implementation of managed clean and healthy in the area of CDW is essential for the environment and for the economy of the cities, who are spending less resources on the collection, cleaning of drains and treatment of diseases. Nowadays, the amount of waste generated is considered large, occupying much space in landfills, and its transportation, depending on the volume and weight, is quite expensive. Recycling and reuse of these wastes are extremely important to control and mitigate environmental problems, as well as produce various materials value-added. Over 90% of waste can be recycled, reused and transformed into aggregates with characteristics very similar to the original product, thus creating environmentally friendly products such as sand, gravel, pebbles. This research concerns the study of the properties of concrete containing CDW, aiming its use in the manufacture of concrete blocks to seal without structural function. Blocks have been molded with partial replacement of natural aggregates by recycled aggregates and later were performed tests of compressive strength in accordance with the standards to prove the technical feasibility of the material for the trait studied.

UTILIZAÇÃO DE RESÍDUOS POLIMÉRICOS DA INDÚSTRIA DE RECICLAGEM DE PLÁSTICO EM BLOCOS DE CONCRETO

The fate of polymeric wastes for purposes other than those landfills, such as use in concrete blocks, is characterized as an important measure of recovery of solid waste and reducing waste of raw materials. Thus, this study was aimed to analyze the technical feasibility of using waste polymeric stranded segment of plastic industries in the production of concrete blocks. To achieve this goal, the material was ground in generating company in the plastics and sent to study the production of concrete blocks in company specializing in the business. Soon after, the block went for tests of Compressive Strength, Verification surface, dimensional analysis, Water absorption and leaching. Performed tests, it was observed that only approved the bricks with 5% plastic, which did not present any problem structure and therefore concluded ideal as the percentage of incorporation of such material into concrete blocks.

Concrete block production from construction and demolition waste in Tanzania

In Tanzania, construction and demolition (C&D) waste is not recycled and knowledge on how it can be recycled especially into valuable products like building materials are still limited. This study aimed at investigating the possibility of recycling the C&D waste (mainly cementitious rubble) into building material in Tanzania. The building materials produced from C&D waste was concrete blocks. The concrete blocks were required to have a load bearing capacity that meets the building material standards and specifications. Eight C&D waste samples were collected from C&D building sites, transported to the recycling site, crushed, and screened (sieved) to get the required recycled aggregates. Natural aggregates were also used as control. The recycled aggregates were tested in the laboratory following the standard methods as specified in Tanzanian standards. The physical, mechanical and chemical characteristics were determined. The physical and mechanical results showed that recycled aggregates were weaker than natural aggregates. However, chemically they were close to natural aggregates and therefore suitable for use in new concrete block production. In the production process, each experiment utilized 100% recycled aggregates for both fine and coarse portions to replace natural aggregates. The Fuller's maximum density theory was used to determine the mix proportions of materials in which a method that specifies concrete mix by system of proportion or ratio was used. The concrete blocks production processes included batching, mixing (that was done manually to get homogeneous material), compacting and moulding by hand machine and curing in water. After 28 days of curing, the concrete blocks were tested in the laboratory on compressive strength, water absorption ratio and density. The results showed that the blocks produced with 100% recycled aggregates were weaker than those with natural aggregates. However, the results also showed that there is a possibility of recycling the C&D waste into building material because 85% of the tested concrete block specimens from recycled aggregates achieved a compressive strength of 7N/mm2, which is defined as the minimum required load bearing capacity in Tanzania. Therefore, the C&D waste could be a potential resource for building material production for sustainable construction in Tanzania rather than discarding it. Further work should focus on the economic feasibility of production of concrete blocks with recycled aggregates in Tanzania.

Using recycled concrete aggregates in precast concrete hollow blocks

AbstractAmong the construction waste that could be recycled, we can mention the aggregates resulting from crushed concrete. While the acquired knowledge about the use of recycled aggregates in new concrete mixes is fairly large, the use of such aggregates in the production of concrete blocks is very limited. This research aims to study the influence of the use of recycled aggregates in precast concrete hollow blocks on their compressive strength. Tests were carried out to determine the rate of recycled aggregates content to be used in the manufacture of concrete blocks in order to obtain blocks having suitable compressive strength. Tests were executed on several series of blocks whose composition includes recycled aggregates and on one series of reference blocks whose composition consisted exclusively of natural aggregates. Tests results have provided the maximum percentage of recycled aggregates that can be included in new concrete block mixes without affecting blocks compressive strength. Tests have shown that the use of recycled aggregates in concrete blocks could give a compressive strength similar to that of blocks manufactured without any recycled aggregates. It has been shown also that using recycled aggregates in the manufacture of concrete blocks without any natural aggregates is not economical at all because of the need to add a relatively high quantity of cement necessary to obtain the required compressive strength.

Study of the reuse of construction residues in concrete employed by blocks manufacture

The use of construction and demolition waste (CDR) comes as an alternative for recycling, for costs reduction and for raw material. The CONAMA Resolution 307 (National Council for the Environment) establishes that all cities should find an environmentally correct destination to CDR. In this research the mechanical properties of the concrete containing CDR were analyzed aiming its use in the production of concrete blocks. Here, increasing percentages of aggregates of CDR with the same granulometry an substitute the natural aggregate, and then concrete blocks were molded. Tests were then performed in order to determine the compression strength according to NBR 12118:2007, at ages of 14 days and 28 days. It was noticed that the values resulting from the compression strength test were also influenced by the increasing substitution of CDR percentages to the mixture. This research discusses the great potential of using this material in substitution to the natural aggregates used in the production of concrete based materials such as blocks.

Thermal conductivity of lightweight aggregate based on coal fly ash

The article presents the results of physical and chemical properties of lightweight aggregates (LWA) obtained by the thermal treatments of raw composition based on fly ash, supplied by electric plants from Serbia. The production process of LWA consists of raw material preparation, plastic shaping–extrusion, granulation, and thermal treatment at three temperatures: 1100, 1150, and 1200 °C. The final firing temperature (T = 1150 °C) is chosen based on the mechanical and physical properties of the designed aggregates. The particle-size distribution of the LWAs is unimodal (d ≈ 16 mm) while the density value varies from 0.98 to 1.99 g/cm3. The water absorption values are determined by use of two methods: 24 h of soaking in cold water and 5 h of boiling. The thermal conductivity of unbound, fired LWA particles is determined by measuring the amount of axially transferred heat in the stationary state. The obtained value of the LWA thermal conductivity (λ = 0.0872 W/mK, T = 1150 °C) is suitable for the production of structural concrete blocks with improved thermal insulating properties. Because of their high-porosity and -compressive strength values, the designed LWA could be used instead of the conventional aggregates in the production of concrete blocks. Consequently, a real valorization of the waste material such as fly ash in Serbia was established.

TEKNOLOGI PEMBUATAN BAHAN BANGUNAN BERBAHANPASIR (BATAKO) HASIL ERUPSI MERAPIDI LERENG BAGIAN UTARA

The program of the production technology application of the sandbasedbuilding material aims to equip the community of Desa Kalibeing,Kecamatan Dukun, Central Java with: (1) life skill of vocational skill insand-based building material production, (2) enterpreneurship interest inbuilding material production, and (3) capability to develop sand-basedbuilding material production industry.The technology application method consists of the activities: (1)survey of the skill types interested by the target community, (2) talk of lifeskill education related to sand-based building material production, (3)discussion, (3) demonstration, (4) practice of concrete block production, and(5) laboratory test to observe the product quality and analysis of the trainingproduct economic value. The talk and discussion methods are used todeliver the raw material preparation subject, the demonstration and practicemethods are used to equip the community the skill in concrete blockproduction, and the laboratory research aims to observe the quality andeconomic value of the products. The target community of the technologyapplication is the community of Desa Kalibening, Kecamatan Dukun,Central Java. The activity result is analysed by observing the level of thecapability of the training participants in producing sand-based buildingmaterial especially concrete blocks and the quality of the training resultproducts if compared to the existing standards and the selling value of theproducts.The result of the technology application implementation of the sandbasedbuilding material production is the community mastering the skills of:(1) good preparation of raw material to form the concrete blocks, (2)capability of producing sand-based building material especially the concreteblocks with various mixing ratios, (3) treatment of the produced buildingmaterial, and (4) enterpreneurship capability of producing sand-basedbuilding materials especially concrete blocks. Generally the buildingmaterial products made by the target community have met the requirementsset in SNI although they are still in the lowest quality category (A1). Theselling value of the concrete blocks with the ratio of 1 SP : 10 PS is Rp2.000,00 each and the ratio of 1 SP : 12 PS is Rp 1.800,00 each.

Use of wastes derived from earthquakes for the production of concrete masonry partition wall blocks

Utilization of construction and demolition (C&D) wastes as recycled aggregates in the production of concrete and concrete products have attracted much attention in recent years. However, the presence of large quantities of crushed clay brick in some the C&D waste streams (e.g. waste derived collapsed masonry buildings after an earthquake) renders the recycled aggregates unsuitable for high grade use. One possibility is to make use of the low grade recycled aggregates for concrete block production. In this paper, we report the results of a comprehensive study to assess the feasibility of using crushed clay brick as coarse and fine aggregates in concrete masonry block production. The effects of the content of crushed coarse and fine clay brick aggregates (CBA) on the mechanical properties of non-structural concrete block were quantified. From the experimental test results, it was observed that incorporating the crushed clay brick aggregates had a significant influence on the properties of blocks. The hardened density and drying shrinkage of the block specimens decreased with an increase in CBA content. The use of CBA increased the water absorption of block specimens. The results suggested that the amount of crushed clay brick to be used in concrete masonry blocks should be controlled at less than 25% (coarse aggregate) and within 50–75% for fine aggregates.

Strength of masonry blocks made with recycled concrete aggregates

The idea of recycling concrete of demolished buildings aims at preserving the environment. Indeed, the reuse of concrete as aggregate in new concrete mixes helped to reduce the expenses related to construction and demolition (C&D) waste management and, especially, to protect the environment by reducing the development rate of new quarries. This paper presents the results of an experimental study conducted on masonry blocks containing aggregates resulting from concrete recycling. The purpose of this study is to investigate the effect of recycled aggregates on compressive strength of concrete blocks.Tests were performed on series of concrete blocks: five series each made of different proportions of recycled aggregates, and one series of reference blocks exclusively composed of natural aggregates. Tests showed that using recycled aggregates with addition of cement allows the production of concrete blocks with compressive strengths comparable to those obtained on concrete blocks made exclusively of natural aggregates.

Processing Lightweight Aggregate to produce Lightweight Concrete

The modern techniques development used in the production of concrete led to the emergence of types of concrete with different densities compared to normal concrete . This research aimed manufacturing types of lightweight aggregate (coarse and fine) and then the production of lightweight concrete blocks with a good thermal insulation , by using available locally materials . Two types of lightweight aggregate , have been produced by using two methods of manufacturing , first type , where AL-Hadbaa aggregate , produced from Clay , which is on the edge of the Tigris river in Mosul , using 50% Clay and 50% silt , the density obtained about 860 Kg/m3 . The second AL-Rabean aggregate , was the adoption of natural laminated Clay which is located in Nineveh province , in very large quantities , it's mineralization is Montmurlite and kaolinite , density obtained was 750 Kg/m3 , this type did not produce in Iraq and which it's manufactured method simple and economic . The standard tests have been made and were adopted in the production of concrete blocks , lightweight concrete block produced from AL-Hadbaa aggregate , used in bearing walls , have 28 – day compressive strength 15.33 N/mm2 and density about 1770 Kg/m3 . The AL-Rabeaan aggregate used to product concrete block for the purposes of thermal insulation , it's thermal conductivity coefficient was 0.55 W/m.kcal and have a density 1640 Kg/m3 . Keywords : Clay , lightweight aggregate , concrete block

Properties of concrete blocks prepared with low grade recycled aggregates

Low grade recycled aggregates obtained from a construction waste sorting facility were tested to assess the feasibility of using these in the production of concrete blocks. The characteristics of the sorted construction waste are significantly different from that of crushed concrete rubbles that are mostly derived from demolition waste streams. This is due to the presence of higher percentages of non-concrete components (e.g. >10% soil, brick, tiles etc.) in the sorted construction waste. In the study reported in this paper, three series of concrete block mixtures were prepared by using the low grade recycled aggregates to replace (i) natural coarse granite (10mm), and (ii) 0, 25, 50, 75 and 100% replacement levels of crushed stone fine (crushed natural granite <5mm) in the concrete blocks. Test results on properties such as density, compressive strength, transverse strength and drying shrinkage as well as strength reduction after exposure to 800 degrees C are presented below. The results show that the soil content in the recycled fine aggregate was an important factor in affecting the properties of the blocks produced and the mechanical strength deceased with increasing low grade recycled fine aggregate content. But the higher soil content in the recycled aggregates reduced the reduction of compressive strength of the blocks after exposure to high temperature due probably to the formation of a new crystalline phase. The results show that the low grade recycled aggregates obtained from the construction waste sorting facility has potential to be used as aggregates for making non-structural pre-cast concrete blocks.

The effect of aggregate-to-cement ratio and types of aggregates on the properties of pre-cast concrete blocks

The effects of aggregate-to-cement (A/C) ratios and types of aggregates on the properties of pre-cast concrete blocks are evaluated in this study. A/C ratios between three and six and three types of aggregates (i.e., natural crushed aggregate (NCA), recycled crushed aggregate (RCA) and recycled crushed glass (RCG)) were used in the experiments. It was found that the compressive strength of the paving blocks decreased as the A/C ratio increased. The results showed that the strength was directly proportional to the crushing strength of the aggregates (i.e., 10% fines value). Moreover, the water absorption of the blocks had a good correlation with the water absorption ability of the aggregate particles. The use of RCA as a replacement of NCA in the production of concrete blocks reduced the density and strength but increased the water absorption of the blocks. However, the potential high water absorption of the blocks as a result of the incorporation of RCA could be ameliorated by the use of RCG since RCG particles had a low water absorption value.

Utilization of secondary lead slag as construction material

Secondary lead slag, a waste product from battery smelting using CaCO 3 as flux, has been investigated for its use as an admixture and/or aggregate in the production of concrete blocks. The slag was added as partial replacements of cement and/or aggregate. The results revealed that the oxide components of the slag were similar to those of ordinary Portland cement (OPC). The CaO content in the slag is 6.2 times less than that in OPC, while its iron content, as FeO, is 15.1 times higher. Interestingly, it also possesses magnetic property. All samples exhibited higher compressive strengths than that of the sample without slag (STD) which increased with increasing the slag contents and ages. The highest compressive strength was of the sample containing 20% slag as cement substituent and 100% slag as aggregate replacement owing to 259% of that of the STD at 60 days. All samples showed higher water absorption than that of the STD. The higher the slag contents, the more the water absorption. The absorption was, as expected, decreased with ages. Magnetic property of the slag plays an important role in the properties of the concrete blocks. For environmental concern, leachability of lead (Pb) from all samples was also carried out.

Solid waste from aluminum recycling process: characterization and reuse of its economically valuable constituents

Due to economic advantages, many companies in Brazil recover Al from the process of crushing and water-leaching of secondary aluminum dross. Wastes from this process (non-metallic products and salts) are usually landfilled or disposed without treatment, causing many environmental damages. The purpose of this work is to investigate, in a recycling company sited in São Paulo metropolitan area (Brazil), the potential use of the non-metallic product (NMP) in the production of concrete blocks and to evaluate the presence of important chemical compounds that may be useful for other applications. Chemical and mineralogical analyses revealed that NMP is composed of refractory and abrasive oxides (α-Al 2O 3, MgAl 2O 4, SiO 2) and an important source of transition alumina: α-Al(OH) 3. Concrete blocks were made by adding two parts of NMP to one part of cement and four parts of sand. The blocks were tested according to the Brazilian standard (NBR7173/1982) and they passed dimension, humidity and absorption tests but not compressive strength tests. However, particular NMP constituents have accelerated the strength rate development of the blocks, thus decreasing working time. The commercial use of NMP can reduce the amount of discarded wastes contributing to environmental preservation.

Recycled construction debris as an aggregates. Production of concrete blocks

This paper analyzes the use of recycled construction and demolition debris as aggregate for the construction of concrete blocks to be used in sealing masonry. Initial studies addressed the definition of parameters used in the mix of conventional materials (traditionally used in the production of concrete blocks), involving cylindrical test specimens (100x200 mm), molded with the help of a vibratory table. In addition to these definitions, and based on the mixes showing the best results, a new granulometric range was established, against which the granulometry of the recycled aggregates was adjusted. After the initial studies, concrete blocks were molded with the following dimensions: 100x190x390 mm). Studies have determined the behavior of aggregates in relation to mold humidity specific mass, water absorption, and compression resistance in view of the percentage of recycled debris that composes the total aggregate. For the most part, results suggest that construction and demolition debris can potentially be used in the production of concrete blocks, as well as in other pre-molded artefacts.