Lightweight Concrete Precast Panels for the Improvement of Thermal Insulation of Housing with Expanded Polystyrene Beads

2021 ◽  
Vol 1033 ◽  
pp. 163-171
Author(s):  
Alexandra Reto ◽  
Renzo Sanabria ◽  
José Rodriguez ◽  
Alexandra Hinostroza
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Linear Trend ◽  
Precast Concrete ◽  
Expanded Polystyrene ◽  
Dry Density ◽  
Conventional Concrete ◽  
Polystyrene Beads

The precast concrete elements in the construction of buildings are increasingly used due to their better quality control, constructive speed, reduction of the number of workers and less waste of resources compared to conventional construction; for wall applications, to these advantages, the design to ensure thermal comfort requires the improvement of the low thermal insulation of conventional concrete panels. The use of materials with lower thermal conductivity such as Expanded PolyStyrene Beads (EPSB) in lightweight concrete for the construction of precast panels in housing, contributes to improve thermal insulation and the saving operational energy during its operation phase, because the aggregate has a small size, low density and thermal conductivity; applied in higher volumes in concrete, reduces indoor heat loss in cold climates and indoor heat gain in warm climates in housing. The purpose of this research is to study the behavior of lightweight concrete with EPSB for 16%, 26% and 36% addition and evaluate the air-dry density, compressive strength, thermal conductivity, relationship between air-dry density with compressive strength and thermal conductivity. The results indicate that the higher the percentage of EPSB the air-dry density, compressive strength and thermal conductivity decrease; the relationships between air-dry density with compressive strength and thermal conductivity follow a linear trend and are similar.

scholarly journals Novel Core-Shell Non-Sintered Lightweight Aggregate Concrete for Better Properties in Wallboard

2021 ◽  
Author(s):  
Chaoming PANG ◽  
Xinxin MENG ◽  
Chunpeng ZHANG ◽  
Jinlong PAN
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Dry Density ◽  
Core Shell ◽  
Aggregate Concrete ◽  
The Core

Abstract Shrinkage of foam concrete can easily cause cracking and thus makes it difficult for a manufacturer to maintain quality. The density of lightweight aggregate concrete is too high to meet specifications for lightweight and thermal insulation for wallboard. Two types of concrete with dry density in the range 1000–1200 kg/m3 for use in wallboard were designed and prepared using foam and lightweight aggregate. The properties of porous lightweight aggregate concrete with core-shell non-sintered lightweight aggregate were compared with sintered lightweight aggregate concrete along with several dimensions. The two aggregates were similar in particle size, density, and strength. The effects of each aggregate on the workability, compressive strength, dry shrinkage, and thermal conductivity of the lightweight concrete were analyzed and compared. Pore structures were determined by mercury intrusion porosimetry and X-ray computed tomography. Compressive strength ranged from 7.8 to 11.8 MPa, and thermal conductivity coefficients ranged from 0.193 to 0.219 W/m/K for both types of concrete. The results showed that the core-shell non-sintered lightweight aggregate bonded better with the paste matrix at the interface transition zone and had a better pore structure than the sintered lightweight aggregate concrete. Slump flow of the core-shell non-sintered lightweight aggregate concrete was about 20% greater than that of the sintered lightweight aggregate concrete, 28d compressive strength was about 10% greater, drying shrinkage was about 10% less, and thermal conductivity was less. Porous lightweight aggregate concrete using core-shell non-sintered lightweight aggregate performs well when used in wallboard because of its low density, high thermal insulation, and improved strength.

scholarly journals Production of lightweight Geopolymer concrete using artificial local lightweight aggregate

2018 ◽  
Vol 162 ◽  
pp. 02024
Author(s):  
Waleed Abbas ◽  
Wasan Khalil ◽  
Ibtesam Nasser
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Experimental Tests ◽  
Pulse Velocity ◽  
Dry Density ◽  
Geopolymer Concrete

Due to the rapid depletion of natural resources, the use of waste materials and by-products from different industries of building construction has been gaining increased attention. Geopolymer concrete based on Pozzolana is a new material that does not need the presence of Portland cement as a binder. The main focus of this research is to produce lightweight geopolymer concrete (LWGPC) using artificial coarse lightweight aggregate which produced from locally available bentonite clays. In this investigation, the binder is low calcium fly ash (FA) and the alkali activator is sodium hydroxide and sodium silicate in different molarities. The experimental tests including workability, fresh density, also, the compressive strength, splitting tensile strength, flexural strength, water absorption and ultrasonic pulse velocity at the age of 7, 28 and 56 days were studied. The oven dry density and thermal conductivity at 28 days age are investigated. The results show that it is possible to produce high strength lightweight geopolymer concrete successfully used as insulated structural lightweight concrete. The 28-day compressive strength, tensile strength, flexural strength, dry density, and thermal conductivity of the produced LWGPC are 35.8 MPa, 2.6MPa, 5.5 MPa, 1835kg/m3, and 0.9567 W/ (m. K), respectively.

scholarly journals Properties and Microstructure Distribution of High-Performance Thermal Insulation Concrete

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2091 ◽  
Author(s):  
Malek Mohammad ◽  
Eyad Masad ◽  
Thomas Seers ◽  
Sami G. Al-Ghamdi
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
High Performance ◽  
Lightweight Concrete ◽  
Concrete Mixture ◽  
Unit Weight ◽  
Expanded Perlite ◽  
Micro Computed Tomography ◽  
Structural Applications

The aim of this experimental study is to develop high strength and lightweight concrete mixture suitable for structural applications. This work investigates the effect of replacing normal aggregate either partially or totally with expanded perlite aggregate. This material allows for better thermal insulation properties, thus decreasing the energy usage within the life cycle of the concrete structure. Expanded perlite aggregate was used in concrete by 20%, 40%, 60%, 80%, and 100% in replacement of the natural aggregate. Material characterization tests of compressive strength, flexural strength, and thermal conductivity were carried out for six concrete mixtures. In addition, microstructure analysis was performed with the aid of a micro-computed tomography system to investigate the effects and relation of microstructure quantities on material properties. The proposed concrete mixture, which has 100% of expanded perlite aggregate, has a unit weight of 1703 kg/m3 and achieved reduction percentage of thermal conductivity around 62% (1.81 to 0.69 W·m−1·K−1) and a compressive strength of 42 MPa at 28 days; and thus is ideal for structural applications with enhanced properties.

Study on Preparation and Properties of Cement-Based Foamed Lightweight Thermal Insulation Material

2011 ◽  
Vol 306-307 ◽  
pp. 994-997
Author(s):  
Cong Cong Jiang ◽  
Guo Zhong Li ◽  
Shui Zhang
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Fly Ash ◽  
Thermal Insulation ◽  
Thermal Conductivity Coefficient ◽  
Steel Slag ◽  
Activation Mechanism ◽  
Dry Density ◽  
Insulation Material ◽  
Thermal Insulation Material

A cement-based foamed lightweight thermal insulation material was prepared with cement, industrial waste (fly ash, steel slag) as the main raw materials, by using self-developed composite activator and foaming agent. The influence of foam content on dry density, compressive strength and thermal conductivity coefficient of material was studied, the activation mechanism of composite activator to fly ash and steel slag was discussed. Results showed that, the dry density and compressive strength of material decreased, and thermal conductivity coefficient decreased first and then increased with the increasing foam content.

scholarly journals Lightweight geopolymer composites as structural elements with improved insulation capacity

2018 ◽  
Vol 149 ◽  
pp. 01042 ◽  
Author(s):  
Glikeria Kakali ◽  
Dimitris Kioupis ◽  
Aggeliki Skaropoulou ◽  
Sotiris Tsivilis
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Lightweight Concrete ◽  
Construction Materials ◽  
Expanded Polystyrene ◽  
Structural Elements ◽  
Cement Mortars ◽  
Mechanical Strengths ◽  
Geopolymer Composites ◽  
Excellent Stability

This study concerns the development of lightweight fly ash based geopolymers which can be applied as alternatives to the traditional lightweight concrete. Different kinds of expanded polystyrene were used as lightweight agents. The results showed that lightweight geopolymers were successfully prepared, exhibiting compressive strength and density in the range 7.70 – 29.57 MPa and 0.97 – 1.57 g/cm3, respectively. The product containing 3% w/w of commercial expanded polystyrene possesses low thermal conductivity (0.16 W/mK) combined with sufficient mechanical strengths (11 MPa), excellent stability and fire resistance while its water absorption is comparable to that of conventional construction materials (cement mortars, concrete).

scholarly journals Effect of Polypropylene Fibres on the Thermal Conductivity of Lightweight Foamed Concrete

2018 ◽  
Vol 150 ◽  
pp. 03008 ◽  
Author(s):  
Ashfaque Ahmed Jhatial ◽  
Wan Inn Goh ◽  
Noridah Mohamad ◽  
U. Johnson Alengaram ◽  
Kim Hung Mo
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Urban Areas ◽  
Dry Density ◽  
Polypropylene Fibres ◽  
Conventional Concrete ◽  
Thermal Insulating ◽  
Foamed Concrete ◽  
Permanent Load

With the reduction in the permanent load on the structure and excellent insulation properties, the lightweight foamed concrete is a potential thermal insulating building material to counter the urban heat island effect, which increases the temperature of urban areas due to the concentration of infrastructures constructed using conventional concrete that absorbs the solar radiation. The lightweight foamed concrete whose dry density ranges from 400 kg/m3 to 1600 kg/m3, has lower thermal conductivity compared to conventional concrete. But reduced density attributes to reduced compressive strength. In this study, to enhance the mechanical properties, the foamed concrete of 1600 kg/m3 density is reinforced with polypropylene fibres (PP). Four percentages of PP fibres, 0% (controlled), 0.2%, 0.25% and 0.30% were added into the foamed concrete. The compressive strength as well as the thermal conductivity of foamed concrete reinforced with PP fibres were determined. Based upon the findings, the optimum percentage of PP was determined to be 0.20% which gave higher compressive strength while thermal conductivity of foamed concrete was observed to decrease upon addition of PP fibres. Thus, addition of PP fibres improves the thermal resistance in the foamed concrete along with enhancing the mechanical properties.

scholarly journals THE RELATIONSHIPS BETWEEN COMPRESSIVE STRENGTH AND DENSITY OF POLYSTYRENE LIGHTWEIGHT CONCRETE AND THEIR COMPONENT RATIOS

2020 ◽  
pp. 1-11
Author(s):  
Mohammed Al-lami ◽  
Emad Al-saadi
Keyword(s):  
Compressive Strength ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Experimental Program ◽  
Dry Density ◽  
Low Density ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Lining Material ◽  
Mathematical Relationships

The research deals with the properties of lightweight concrete, made from polystyrene, cement, sand and water, namely the compressive strength and density. This type of lightweight concrete is characterized by thermal insulation, low density and good compressive strength compared to other types of lightweight concrete. It is used as a lining material in inclination surfaces and in the production of unloaded building units and elements. The aim of this paper is to develop mathematical relationships between compressive strength and density of concrete and their mix proportions such as sand to cement ratio (S/C), water to cement ratio (W/C) and polystyrene to cement ratio (P/C). An intensive experimental program has been conducted. From the results of the tests, a mathematical relationships were suggested to find the proportions of components based the required compressive strength and dry density.

scholarly journals Experimental Investigation of the Production of Sustainable Lightweight Concrete

2020 ◽  
Vol 38 (11A) ◽  
pp. 1652-1665
Author(s):  
Mouhammed J. Lafta
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Dry Density ◽  
Normal Concrete ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Concrete Production ◽  
Concrete Mix

An experimental study on four types of coarse aggregate was conducted to produce lightweight concrete. These four types are namely; white limestone, red limestone, clay brick fragments, and pumice. Ordinary Portland cement was used for all examined mixes. Water to cement ratio (w/c) was modified according to the effect of coarse aggregate type on the workability of the resulted concrete for each mix. The reference concrete mix, which is normal concrete, water to cement ratio used was (0.5). The investigated characteristics for all concrete mixes were workability, compressive strength, dry density, absorption, and thermal conductivity. Results indicated that the aggregate type significantly affects most of the properties of lightweight concrete mixes such as workability, density, and thermal insulation for all tested types of concrete. All investigated specimens indicated improvement in terms of density, workability, and thermal conductivity when compared to the reference concrete mix. Yet, it was derived from the testing results that using pumice in lightweight concrete production is the optimum option among the other examined types. When compared to normal concrete, this type of lightweight concrete showed a 41% decrease in dry density, nearly 72.54% decrease in thermal conductivity, and about 12% increase in workability. However, it is vital to notice that due to the low compressive strength and the relatively high absorption capability for all the examined types of lightweight concrete, it is suggested to use these types of concrete for non-structural walls that are not subjected to or exposed to high humidity.

scholarly journals Analysis of new inorganic exterior insulation materials and thermal energy storage

2020 ◽  
Vol 24 (5 Part B) ◽  
pp. 3195-3203
Author(s):  
Jianying Wang
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Glass Bead ◽  
Water Retention ◽  
Raw Materials ◽  
Retention Rate ◽  
Cellulose Ether ◽  
Dry Density ◽  
Insulation Materials

In order to reduce the energy efficiency of the construction industry and improve the building safety, in this research, a new type of inorganic insulation material ? vitreous bead insulation mortar is studied and its properties are analyzed. Quantitative method is used to analyze the influence of glass bead mixing amount, cellulose ether mixing amount and redispersible emulsion powder mixing amount on the consistency, water retention rate, dry density, softening coefficient and compressive strength of glass bead insulation mortar. The effect of different raw materials allocation on the thermal conductivity of vitrified microbeads thermal insulation mortar is explored. The results show that the performance of insulation mortar decreases significantly with the increase of glass bubbles. With the increase of cellulose ether content, the consistency and compressive strength of insulation mortar first increased and then decreased, the water retention rate increased significantly, but the dry density decreased significantly. With the increase of the content of redispersible emulsion powder, the consistency and compressive strength of insulation mortar first increased and then decreased, but the dry density decreased gradually. Glass bubbles and fly ash parameters are the main factors that affect the thermal conductivity of thermal insulation mortar, and their thermal conductivity decreases with the increase of the proportion of air-entraining agent. As a result, the performance of vitreous microbeads thermal insulation mortar will change to a certain extent with the different proportion of raw materials, which provides data support for the preparation and application of inorganic external wall thermal insulation materials.

The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Agricultural Waste ◽  
Hydraulic Press ◽  
Dry Density ◽  
Olive Stone ◽  
Compressed Earth Blocks ◽  
Clay Matrix ◽  
Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

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