Conventional Concrete Blocks Research Articles

Lateral force–displacement relationships for shallowly buried pipe reinforced by geocells

Geocell reinforcements are proposed as a thrust countermeasure for shallowly buried pipeline bends and tees. The proposed method is easy to construct and has shorter construction time than the use of conventional concrete blocks since it does not require curing. Lateral loading tests were conducted on plates reproducing pipe bends or tees to verify their effectiveness while understanding deformation mechanisms. In addition to changing the plate width and geocell pocket size, additional experiments were conducted with different geocell reinforcement dimensions, geocell tensile stiffnesses and tensile properties of the seams. An equation for predicting the force–displacement relationship was developed as part of the proposed design method. The experimental results showed that the sides of the reinforced ground were not fully integrated when the width of the geocell reinforcement was large relative to the plate width. It was also found that the maximum force hardly decreased, although the displacement increased slightly due to the reduction of the tensile stiffness of the geocells and the tensile force at the geocell seams. Moreover, a hyperbolic approximation of the force–displacement relationship of the geocell reinforcement was developed and the calculated values agreed well with the experimental values.

Investigation of Recycled Plastic Waste into Bricks for the Construction of Housing Projects in Ghana

Alternative materials are now being used for the construction of various projects in Ghana due to the expansion of infrastructure in the country. The quantity of materials needed to build infrastructure presents a significant opportunity to reuse some of the waste products. It has become possible to investigate the recycling of plastic waste into the construction of bricks due to the substantial discrepancy between the supply and demand of traditional building materials. In this study, an effort was made to recycle a sizable amount of HDPE waste gathered from markets, shopping centers, landfills, and supermarkets for utilization of bricks for housing projects. To determine the efficacy and durability of the bricks made from recycled plastic waste for various uses in civil engineering projects, several experimental tests including the compressive strength test, split tensile test, and water absorption tests were conducted. The mix ratios for the plastic bricks for compressive and tensile strength are 1:3, 1:4, and 1:5.5, respectively, while their water absorption mix ratios are 1:2, 1:3, and 1:4. The experimental findings demonstrated that the bricks produced had good compressive strength, tensile strength and low water absorption rates. Additionally, it was observed that the manufactured bricks are lightweight, have a smooth surface and fine edges, and can be an excellent substitute for clay and conventional concrete blocks, which have been used for decades to build housing projects in the country.

An Experimental Study of Transparent Concrete by Using Optical Fibers

Abstract: Transparent concrete is the new type of concrete introduced in the modern era which carries special property of light transmitting due to presence of optical fibers & is also known as translucent concrete or light transmitting concrete. It is lighter than conventional concrete having special features such as low density and thermal conductivity with main advantage of reduction in dead weight, faster building rate in construction, lower haulage & handling cost. Light is transmitted from one surface of the brick wall to the other due to glass rods along the overall width of the wall which allows light to pass through. An optical glass fiber (or optical fibre) is a flexible, transparent fibre made of glass (silica)or plastic, slightly thicker than a human hair & can function as waveguide, or “light pipe” to transmit light between the two ends. Main aim of the study is to design translucent concrete blocks with the use of glass rods with sand & cement then analyse their various physical & engineering properties with respect to conventional concrete blocks by adding glass rods of 1%, 2 %, 3 % 4 % 5% at 1.5 cm spacing

APPLICATION OF POROUS CONCRETE FOR NATURAL SLOPE PROTECTION

Natural slope protection is challenging all over the country. The study assessed the application of newly designed porous concrete block over conventional concrete block in slope protection. In the study, four different types of concrete blocks were designed; three of them were 8″×8″×3″ and one was 9″×9″×3″ in size. One 8″×8″×3″ porous concrete block design was selected based on it’s compressive strength. Another conventional concrete block of same size was selected for comparing the results. After preparation, the porous and conventional concrete blocks were placed on the slope of a selected earthen canal in a 3-row and 11-column format. According to the findings, the porous concrete block was vegetative while the conventional concrete block was not. The porous concrete block required less volume of materials, which reduced the cost by 18.2% over the conventional concrete block. It is concluded that the newly designed porous concrete block is more cost-effective, light-weight, and vegetative-compatible than the conventional concrete block of the same size. Therefore, the study suggests applying the newly designed porous concrete block to protect the natural slope.

Use of marble and granite dust waste as partial replacement of fine aggregates in concrete

The growth in Infrastructural development resulted in fast decline of available natural resources. In contrast the marble and granite production has generated a very huge amount of by-products in the form of fine particles which causes large scale environmental pollution. This has led to a major concern in the environmental as well as construction industry due to the disposal of these million tons of fine particles. The purpose of this study is to experimentally investigate the compatibility of marble and granite dust by-product for replacing of fine aggregates in concrete partly. In this work, a mixture of marble and granite dust in ratio 0.5:0.5 is used as a for replacing of sand in different percentages (10%,20%,30%,40%,50%) by weight and cement is partially replaced with slag (GGBS) by a by 40%. Influence of replacement of sand with marble and granite dust on the strength behaviour on concrete was studied at curing ages 7 and 28 days and the results are compared with conventional concrete blocks. A 20% replacement of fine aggregates with marble and granite dust mixture resulted in 23.34% and 14.4% increase in compressive strength was at 7 and 28 days of curing, as compared to controlled concrete. The results of the experimental study show that, mixture of marble and granite dust can partially be used in place of fine aggregate in concrete and saves considerable amount of sand there by preserving the valuable natural resource resulting in sustainable replacement for sand.

Design, development, and analysis of modified concrete block integrated with thermal energy storage material for regulating indoor temperature

This study shows a comparative analysis of indoor thermal behavior of concrete block embedded with macroencapsulated phase change material with fins and without fins. Concrete blocks of similar dimensions were incorporated with square shape, rectangular shape, cylindrical shape, square shape with fins, rectangular shape with fins, and cylindrical shape with fins macroencapsulated phase change material. Pure paraffin wax (70 wt%) and raw coconut oil (30 wt%) are used as phase change material. Real outdoor testing of all the modified concrete block in comparison with conventional concrete block was conducted for continuous 96 h. Various indoor thermal comfort parameters such as peak temperature, thermal amplitude, and decrement factor were investigated. Additionally, thermographic images were also analysed to understand the effect of incorporating various shapes of macroencapsulated phase change material. Result shows maximum peak temperature reduction of 8.43 °C by concrete block integrated with cylindrical shape macrocapsule with fins. Also, concrete block integrated with cylindrical shape macrocapsule with fins shows highest reduction in indoor thermal amplitude of 26.54 % followed by cylindrical macroencapsulated phase change material without fins in comparison with reference concrete block. Lowest deviation in thermal amplitude shows by rectangular shape macrocapsule with fins. Reduction in decrement factor was also observed in modified concrete blocks in comparison with reference concrete block.

Finite element analysis of single-storey unreinforced alternative masonry walls

The most commonly cited obstacles to the uptake of alternative masonry units on a meaningful scale, despite significant research investment, are a lack of standards and understanding of their structural behaviour. This paper contributes to the body of knowledge on finite element analysis of alternative masonry structures, towards improved understanding of their structural behaviour. Two critical masonry wall configurations, in the context of South African low-income, government-subsidised housing, are analysed using the simplified micro-modelling approach, under ultimate limit state wind and seismic actions. Three alternative masonry materials are characterised and employed in the numerical analyses, geopolymer, compressed-stabilised earth and adobe blocks, as well as conventional concrete blocks as benchmark. Despite the wide spectrum in masonry materials analysed, the chosen modelling approach captured the major failure mechanisms well. The four materials performed as expected relative to one another, but most wall/material configurations failed to resist the required design load, including the conventional concrete masonry material.

Use of Textile Waste as an Addition in the elaboration of an Ecological Concrete Block

The textile industry has grown significantly in recent years, reaching a global fiber production of 53 million tons which 12 % are recycled; Construction sector has been using more and more recycled materials from different industrial sources, to apply them in their constructions and to reduce CO2 emissions and final energy consumption. The present study aims to study the behavior of concrete blocks of f´c = 210 kg/cm2 adding polyester textile waste with 3 %, 6 %, 9 %, 12 % and 15 %; void content, compressive strength and thermal conductivity decrease, and water absorption, acoustic insulation and unit price increase by 3 %, 34 % and 16 % compared to conventional concrete block.

Optimization of Mix Proportions for Novel Dry Stack Interlocking Concrete Blocks Using ANN

This paper proposes novel concrete interlocking blocks made of fly ash and GGBS which are an alternative for the conventional concrete blocks. The artificial neural network (ANN) technique is used to estimate the mechanical strength of interlocking blocks and is verified with experimental investigation. The ANN model is based on the Levenberg–Marquardt principle which is executed using MATLAB. The inputs are given in the percentage ratio of cement: fly ash: crushed stone aggregate (FA): coarse aggregate (CA) for the process of learning, testing, and validation. The selected model is subjected to several trials in terms of mean square error, containing 4 input, 2 sets of 10 hidden layers, and one output components. In this study, a total of 2600 blocks of different mixes were tested as per IS 2185‐1 (2005) to assess 3, 7, 14, 21, and 28 days’ strength. The experimental investigations were carried out in two phases. In the first phase, experimental investigations to identify the optimum mix proportions of cement, aggregate, fly ash, and ground granulated blast furnace slag to achieve desired compressive strength was carried out. In the second phase, the identified mix proportions were analysed using ANN to predict the compressive strength of interlocking blocks. The results indicate that the proposed ANN model developed to determine the mechanical strength and cost of interlocking blocks has excellent prediction ability.

Design and Application of Cellular Concrete on a Mexican Residential Building and Its Influence on Energy Savings in Hot Climates: Projections to 2050

The thermal performance of economical housing located in hot climates remains a pending subject, especially in emerging economies. A cellular concrete mixture was designed, considering its thermophysical properties, to apply the new material into building envelopes. The proposed materials have low density and thermal conductivity to be used as a nonstructural lightweight construction element. From the design stage, a series of wall systems based on cellular concrete was proposed. Whereas in the second phase, the materials were analyzed to obtain the potential energy savings using dynamic simulations. It is foreseen that the energy consumption in buildings located in these climates will continue to increase critically due to the temperature increase associated with climate change. The temperatures predicted mean vote (PMV), electric energy consumption, and CO2 emissions were calculated for three IPCC scenarios. These results will help to identify the impact of climate change on the energy use of the houses built under these weather conditions. The results show that if the conventional concrete blocks continue to be used, the air conditioning energy requirements will increase to 49% for 2030 and 61% by 2050. The proposed cellular concrete could reduce energy consumption between 15% and 28%, and these saving rates would remain in the future. The results indicate that it is necessary to drive the adoption of lightweight materials, so the impact of energy use on climate change can be reduced.

Experimental assessment of the thermal and mechanical performance of insulated concrete blocks

The performance of insulated concrete blocks, with different industrial waste materials, was assessed for improved thermal resistance and mechanical properties. The optimal dosage of polystyrene bead (EPS), low-density polyethylene (LDPE), vermiculite (VL) and volcanic scoria (VS) was initially determined to produce concrete blocks with low thermal conductivity and acceptable compressive strength using low cement content to reduce both the CO2 emission and the cost. Thermal conductivity, compressive strength, density, absorption, cost analysis, and CO2 emission were used to assess the efficiency. The results proved that the thermal conductivity of VS, EPS, LDPE and VL blocks were reduced by about 26.1, 19.4, 17.0 and 16.7%, as compared to that of the normal block. However, the results showed that the reduction in compressive strength was 51, 47, 39, and 37% for VS, VL, LDPE, and EPS blocks, as compared to that of the control block. Further, the vermiculite block exhibited the highest water absorption of all blocks by up to about 14%. Moreover, the results of cost analysis proved that the EPS and VS are the cheapest insulated blocks, as compared to other insulated blocks. Besides, the results support the recommendation to use VS-insulated block because of its lowest thermal conductivity and it satisfied the requirements of compressive strength as non-load bearing walls. It is found that the best wall (VS) can improve the thermal resistance by about 279% when compared to the conventional concrete blocks. This improvement could reduce the cost of energy consumption from 349.3 to 99.4 $/m2 (about 3.5 times of reduction) based on net present value (NPV) over 50 years. The VS-wall could minimize the CO2 by about 3.71 times over the conventional concrete block and about 1.35 times over the control wall. This work has achieved the following dual benefits: conversion of waste polymers into useful materials to produce cheap and sustainable constructional material as well as saving the energy and thus the environment.

Increasing Eco-Performance of Concrete Blocks through Computational Design Form Optimization

This paper presents creative geometry research focusing on computational design exploration to improve the eco-performance of concrete blocks used as a building material. To provide a positive eco-performance, an optimized concrete block was designed to be more efficient than a conventional concrete block with respect to the materials used and the space occupied during storage and transport. The results prove that the form is cost-effective and that the environmental impact caused by associated production and distribution processes would be comparatively reduced. Computational research based on parametric design thinking enabled the relationship between form properties as selected design parameters to be evaluated, with the aim of ensuring that efficiency does not compromise technical requirements and that the overall functional role of the concrete block is appropriate when used as a constituent material in nonstructural wall construction. Volumetric-based measurements were employed using Rhinoceros modeling software with a Grasshopper plug-in to assess the eco-performance of the concrete block based on selected indicators. The results show that the folded S-shape concrete block with a width of 40 mm consumes only 43% of the main material and 14% of the auxiliary material relative to a conventional concrete block with a width of 100 mm. When arranged horizontally, a standard container can hold 60% more of the optimized concrete block units compared to conventional ones. Additional findings were also made that suggest future research potential, including use of the concrete blocks as building elements in passive design strategies.

An integrated life cycle assessment of different façade systems for a typical residential building in Ghana

This study performs a comparative environmental and economic assessment of four different façade systems for low-cost residential buildings in Ghana. A framework is designed to incorporate BIM, Life Cycle Assessment (LCA) and Life Cycle Cost (LCC) to perform a holistic comparison of a Shotcrete Insulated Composite Façade (Shotcrete ICF), Galvanised Steel Insulated Composite façade (G. Steel ICF) and Stabilised Earth Block Façade (SEBF) against the conventional Concrete Block and Mortar Façade (CBMF). BIM models are developed to compute the environmental and economic impacts of each façade. The results are then subjected to a comparative analysis for different life cycle stages. The SEBF is proved to be the most sustainable facade as it reduces cumulative energy demand (CED) by 39.13 %, global warming potential (GWP) by 18.07 % and LCC by 47.87 % compared to CBMF. The Shotcrete IFC and G. Steel IFC are found to increase CED but decrease GWP. Other than the SEBF, the ranking of all façades under different indicators changes through the scenario analysis. The findings of this study provide useful guidelines for selecting facade systems and reducing the environmental and economic impacts of low-cost residential buildings in Ghana.

Control of adiabatic properties using thermal meta-structures

In this study, the shapes and materials of thermal meta-structures, which can suppress as much heat propagation as possible in a structure, were investigated using a three-dimensional finite-difference time-domain technique. The heat flux vibrating in the traveling direction could be suppressed using multiple layers of thermal meta-materials. The heat flux transferred through the gap between thermal meta-structures could also be efficiently suppressed by placing even-numbered layers of thermal meta-structures in a zigzag arrangement in a structure. When the air-based thermal meta-structures were increased from one to four layers, the temperature inside the structure could be reduced from 38.9 °C to 25.5 °C. Moreover, when water-, paraffin-, aerogel-, and air-based thermal meta-structures having different thermal conductivities, densities, and specific heat characteristics were applied to the structure, a temperature of 50 °C to one side led to temperatures of 35.7, 33.4, 25.7, and 25.5 °C on the other. In other words, the temperature of the concrete block with air-based and aerogel thermal meta-structures was more than 13 °C lower than that of a conventional concrete block (38.9 °C), confirming that the insulation effect obtained by suppressing heat transfer was significant.

Study on Behavior of Concrete with Partial Replacement of Fine Aggregate with Waste Plastics

Plastic disposal is one of the major problems encountered in all countries. In India, more than 15,000 tons of plastic wastes are generated every day, of which 6,000 tons remain uncollected and littered as per the Government statics. Reuse of bulky wastes is considered the best environmental alternative for solving the problem of disposal. One such waste is plastic, which could be used in various applications.In this paper we have discussed about the behavior of concrete with partial replacement of fine aggregate with plastic wastes ranging from 15-30% with small grain size are incorporated. Performance of M20 grade of concrete is being studied. The blocks casted using this concrete can be used for dividers and temporary structures. They can also be used for bedding of banks since there is no vertical load acting on them. Slump test, water absorption test, water permeability test and compressive strength test were conducted on the concrete. The compressive strength of waste plastic concrete blocks has increased compared to conventional concrete blocks

Life cycle assessment of emergent masonry blocks

This life cycle assessment evaluates the environmental impacts of two emergent masonry blocks designed to serve as sustainable replacements for conventional masonry blocks. The emergent blocks offer the same strength, durability, and form as conventional structural concrete blocks, and include hollow cores to enable placement of reinforcement in accordance with standard construction practices. The first emergent block consists of stabilized engineered soil that is compacted to reduce the use of ordinary Portland cement and eliminate curing. The second block, which is also compacted, contains alkali activators that promote a geopolymerization reaction among naturally occurring aluminosilicate clays, eliminating the need for ordinary Portland cement. QuantisSuite 2.0 software is used to perform a cradle to gate life cycle assessment comparing the environmental impacts of the two blocks to conventional concrete blocks across a range of indicators. The compacted stabilized soil block offers 46% less embodied carbon than conventional concrete block, which it outperforms in all categories except water consumption. The compacted alkali-activated block reduces embodied carbon by 42% when compared to concrete block, but has a higher impact on ecosystem, water withdrawal and resources. In terms of ecosystem and health indicators, the compacted stabilized soil block is the preferred building block, while conventional concrete block architectural blocks are the most water efficient. As understanding of alkali activation improves and manufacturing of compacted block is optimized, further environmental benefits are possible in both stabilized soil block and the alkali-activated block.

Bloques de concreto con emulsión de parafina

Los muros de las edificaciones presentan frecuentemente problemas de humedad como consecuencia de la exposición a la lluvia y la absorción de agua del suelo. Infortunadamente, los bloques de concreto convencionales adquiridos en el mercado tienen coeficientes de absorción capilar altos y resistencias a la penetración de agua bajas.En esta investigación, se produjeron y analizaron experimentalmente bloques y probetas cilíndricas, se fabricaron con arena de concreto lavada, cemento Portland tipo 1, emulsión de parafina y una relación agua-cemento de 0,40 en peso. Se estudiaron bloques y cilindros sin emulsión de parafina y con 10%, 20%, 30% y 40% de adición de emulsión de parafina respecto al peso del cemento. Se ejecutaron ensayos de absorción capilar, de resistencia a la penetración de agua y se realizó un análisis comparativo de los resultados obtenidos para determinar la proporción óptima de adición de emulsión de parafina.Se determinó que los bloques con emulsión de parafina presentan mejores propiedades que los bloques convencionales sin aditivos y que podrían reducir los problemas de humedad en los muros pues tienen un coeficiente de absorción capilar bajo.

Development of building blocks using vegetable oil and recycled aggregate

The primary objective of this research was to contribute towards greater sustainability of the construction industry in the Qatar by proposing methods to reduce its dependency on primary imported materials. In this investigation, recycled and secondary aggregates (RSA) were combined with non-traditional binders to develop a unique method of manufacturing construction and building blocks. Following an extensive phase of laboratory trials and experimentation, it was realised that many types of graded mineral aggregates, when mixed with vegetable oils (virgin or waste) at optimal proportions, then compacted and thermally cured at elevated temperatures can readily generate hardened composites that have the mechanical characteristics of conventional building blocks. The resultant blocks have been named “Vegeblocks” and are viewed as viable alternatives to conventional concrete blocks. Furthermore, the research has demonstrated the feasibility of producing Vegeblocks composed of 100% recycled aggregate and discarded waste cooking oil. Based on physical and mineralogical properties, each type of aggregate has an optimum oil content for maximum compressive strength, beyond which, any additional oil will result in reduction in mechanical properties. Acceptable compressive strength values were achieved by thermally curing Vegeblocks at of 170 °C for 24 hours.

Effectiveness of nocturnal ventilative passive cooling strategy in the maritime desert climate of the Arabian Gulf region

This paper presents results of the first set of experiments carried out to investigate the potential of nocturnal ventilative cooling techniques in detached residential buildings in the Arabian Gulf region. This experiment is part of a wider research programme in the field of passive solar cooling strategies at the King Faisal University, sponsored by the “Joint United States-Saudi Arabian Program for Cooperation in the field of Solar Energy” (SOLERAS). The experiments were structured to identify the comfort enhancement potential of direct and induced nocturnal convective cooling techniques through the use of controlled ventilation during predetermined periods of favourable ambient conditions. Horizontally placed, vertically hung openings were designed in accordance with the results of the analysis of weather data and located in the North and South walls of the optimum orientation of the full-scale prototype test house. Conventional concrete block, load bearing construction with external insulation and heavy internal thermal mass were used. Fanger Predicted Mean Vote, as a function of dry bulb temperature, wet bulb temperature air velocity, and mean radiant temperature, were calculated and recorded continuously every 3 min of the duration of the experiment. These values have been averaged to evaluate hourly comfort conditions in various zones of the test house. These were compared with the ambient weather conditions during the period of the experiment to evaluate the potential of this passive cooling technique in conserving a very substantial part of the energy wasted in mechanical cooling.