Anderson, J., S. Bartlett, et al. (2012). Development of seismic design approach for freestanding freight railroad embankment comprised of lightweight cellular concrete. GeoCongress 2012: State of the Art and Practice in Geotechnical Engineering, March 25, 2012 – March 29, 2012, Oakland, CA, United states, American Society of Civil Engineers (ASCE).
Recent advances in research, laboratory testing and field evaluations of lightweight cellular concrete have led to an increased understanding about its application as a geomaterial. Recently, lightweight cellular concrete has been used to construct a 40-foot high by 50-foot wide freestanding railroad embankment with vertical sidewalls near Colton, California. The embankment and flyover structures are about 7,000 feet long and consist of 220,000 cubic yards of lightweight cellular concrete. The embankment was designed to support 3 simultaneous Cooper E-80 freight railroad live loads and seismic loading from a 2500-year return period earthquake event. In order to provide an earthquake resilient material, cellular concrete was selected because of its relatively low density (25 to 37 pounds per cubic foot) and high compressive strength (140 to 425 pounds per square inch), when compared with traditional backfill materials. This alternative also provided a reduced embankment footprint and corresponding dead load, which reduced foundation settlement and possible inertial interaction with nearby utilities and infrastructure. Comprehensive seismic design guidance for lightweight cellular concrete embankments has not been fully developed in the U.S, but a rational approach has been developed for freestanding geofoam embankments. A similar approach was incorporated in the design process of the Colton, California embankment. This paper discusses the design process including: (1) selection and development of spectrumcompatible time histories for both horizontal and vertical components of strong ground motion; (2) development of design and evaluation methodologies; (3) detailed numerical evaluation using finite element [QUAKE/W] and finite difference techniques [FLAC 2D]; (4) assessment of the load-deformation characteristics of the embankment system under seismic ground motion and (5) assessment of benefit of shear keys and ground improvement on limiting basal sliding during a seismic event. 2012 American Society of Civil Engineers.
Araujo, E. G. and J. A. S. Tenorio (2005). Cellular concrete with addition of aluminum recycled foil powders. 4th International Latin-American Conference on Powder Technology, November 19, 2003 – November 21, 2003, Sao Paulo, Brazil, Trans Tech Publications Ltd.
Considering its advantage of low density and favorable insulation properties, there are several applications for lightweight autoclaved aerated concrete of uniform cellular structure.The raw materials for the manufacturing of cellular concrete are Portland cement, finely grounded sand and lime. These are batched and mixed with water and metallic aluminum powder finely divided. There is a reaction between the aluminum powder and hydroxides forming millions of hydrogen bubbles throughout the mixture.The aluminum powder is the highest cost component, and the objective of this work is replacing it for another gas forming agent, like recycled foil.The foils are grinded in a high energy ball mill (attritor). Quartz sand is mixed with aluminum foil to reduce the time required for grinding, obtaining spherical particles and ensuring a uniform distribution of aluminum in the gas forming agent.The activity of this gas forming agent was determined by the gas volumetric technique. Average particle size and compressive strength of the samples were measured. The relationship between volume of the gas released during the reaction and milling conditions are presented, showing its viability for producing a high quality cellular concrete.
Bouguerra, A., A. Ledhem, et al. (1998). “Effect of microstructure on the mechanical and thermal properties of lightweight concrete prepared from clay, cement, and wood aggregates.” Cement and Concrete Research 28(8): 1179-1190.
Wood concretes of a clayey matrix are considered herein from the standpoint of developing insulation materials through reliance on local resources and reusing industrial mineral wastes. Both the mechanical and thermal properties of these materials depend heavily on their microstructure and, in particular, on their porous structure which the authors have identified initially. An experimental study of the compression resistance as well as of the thermal conductivity in the dry state and at ambient temperature shows the changes in these characteristics as a function of porosity. A comparison with theoretical models previously tested for other types of cellular materials has served to validate its application in the case of wood concretes of a clayey matrix.
Bouvard, D., J. M. Chaix, et al. (2007). “Characterization and simulation of microstructure and properties of EPS lightweight concrete.” Cement and Concrete Research 37(12): 1666-1673.
EPS concretes are composed of high performance cement mixed with millimetre-size expanded polystyrene spheres. They exhibit a priori contradictory thermal and mechanical features that are suitable for the construction industry. This paper aims at characterizing the microstructure and the properties of EPS concretes and investigating the possibility of predicting these properties through various modelling approaches. It is shown that EPS concretes cannot compete against classical autoclaved cellular concrete in terms of properties but it is however a practical material whose properties can easily be tuned by changing its composition. Modelling should be a useful support for predicting the relation between properties and composition. 2007 Elsevier Ltd. All rights reserved.
Chang, C. J. and Y. C. Chang (2013). Extra-lightweight no-fines cellular concrete – Use for non-structural material. 2013 3rd International Conference on Materials and Products Manufacturing Technology, ICMPMT 2013, September 25, 2013 – September 26, 2013, Guangzhou, China, Trans Tech Publications Ltd.
Over exploitation has led to the destruction of resources and endangered ecological environments. Therefore, research for renewable material has become more important in the construction industry. This study used sintered lightweight aggregate made of clay to replace the coarse and fine aggregate and processed aluminum-wastage to make the foaming agents for cement, producinga brand-new extra-lightweight expanded no-fines cellular concrete. The cellular concrete not only utilizes recycled materials, but also produces an environment-friendly, green building material. Validated throughout the experiment, the cellular concrete may provide functions such as fire protection, thermal resistance, and acoustic absorption when used as non-structural material. This paper attempts to evaluate the basic physical properties of cellular concrete by different water/cement ratio (W/C) and agent/cement (A/C)ratio for the coefficients of expansion, compression strengths, and the thermal conductivity. (2014) Trans Tech Publications, Switzerland.
Degrauwe, D. and G. De Roeck (2004). Experimental and numerical modal analysis of a lightweight steel-concrete composite slab supported by cellular beams. Proceedings of the 2004 International Conference on Noise and Vibration Engineering, ISMA, September 20, 2004 – September 22, 2004, Leuven, Belgium, Katholieke Universiteit Leuven.
The continuous demand for an even more efficient use of materials and economical construction methods has stimulated the development of new types of lightweight construction components. Because of their usually rather complex geometry, it is not feasible to model them in very fine detail. Much more convenient is to model them by simpler elements with equivalent properties. Another problem with these structures is their dynamic behaviour: due to their low mass, they are more vulnerable to dynamic excitations. In this paper, the case of a composite slab, existing of an orthotropic steel-concrete slab and cellular beams, is investigated. An attempt is made to derive equivalent geometrical and material orthotropic plate properties for the steel-concrete slab. The supporting cellular beams are replaced by solid beams with energetically equivalent stiffnesses. With these equivalent elements, a simplified FE-model of the structure is built for modal analysis. In order to improve the correspondence between the FE-model and the real structure, this model is updated, making use of measured modal data. The results of the detailed FE-analysis are compared with approximate manual calculations of the stiffnesses.
Exall, I. (2007). “Aircrete aids sustainability agenda.” Building Engineer 82(8): 18-19.
Aircrete, a lightweight cellular concrete fitted to the Code for Sustainable Homes achieved the highest ratings in the Building Research Establishment (BRE) Green Guide for Housing. The quick-setting thin-layer mortar Celcon aircrete blocks with the thin-joint system is a excellent thermal insulation properties with high percentage of recycled materials. It also helps reduce energy consumption of buildings as well as provides enhanced noise insulation. Meanwhile, all factories are designed to reach the highest standards of energy efficiency and incorporate heat recovery measures and the H+H UK’s manufacturing process has been analyzed and environmentally enhanced. The company was fully complied with ISO 14001 and has operated an environmental management system (EMS). Furthermore, using a combined product- and labor- package H+H’s Ra House system achieved the best.
Farghal Maree, A. and K. Hilal Riad (2014). “Analytical and experimental investigation for bond behaviour of newly developed polystyrene foam particles’ lightweight concrete.” Engineering Structures 58: 1-11.
Structural lightweight concrete (LWC) is of high importance to the construction industry, as it is cost effective and highly advantageous. A new kind of LWC was produced at the Department of Structural Engineering of Ain Shams University in 2005, which combines the advantages of normal density concrete, cellular concrete and high workability concrete through partially replacing the normal weight aggregates with polystyrene foam particles. This leads to concrete’s unit weight reduction while maintaining adequate strength. The latter material can therefore be produced using standard methods familiar to the construction industry with a dry unit weight of 18.50kN/m3, which in turn leads to self weight reduction of 15-20% and the associated decrease in the structure’s overall cost, hence, providing a feasible challenge to normal weight concrete (NWC). The bond behaviour of structural polystyrene foam lightweight concrete (PF-LWC) was investigated analytically and experimentally. The experimental program incorporated two phases. The first phase was performed on the standard pull-out specimens to compare its results with the commonly conducted bond testing and to abstract the bond slip curve of the standard pull-out test specimens. The second phase deal with a deduced beam-end specimen to assess the behaviour of bond between reinforcing bars and concrete in flexure members. Then analytical investigation of the obtained experimental results was performed to develop a model capable of assessing the structural bond behaviour of PF-LWC flexural members. The defining parameters of the bond stress-slip curve were modified for NWC and PF-LWC using the best fit technique to the experimental results in order to add the bar diameter as a variable in the bond stress-slip relationship. The defining parameters of the CEB-FIP 1990 bond stress-slip curve  were modified for NWC and PF-LWC using the best fitting technique. 2013.
Greeley, T. R. (1997). Review of expanded polystyrene (EPS) properties, performance and new applications. Proceedings of the 1997 3rd Symposium on Insulation Materials: Testing and Applications, Third Volume, May 15, 1997 – May 17, 1997, Quebec City, USA, ASTM.
A discussion is provided explaining insulated concrete form systems and structural insulated panels and how the properties of expanded polystyrene (EPS) foams are suited to meet the unique requirements of these systems. The ASTM Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation (C 578) is also discussed. An understanding of the specification allows the proper application of the EPS foams. In addition, a brief history of the development and applications of Geofoams is presented.
Hernandez-Zaragoza, J. B., T. Lopez-Lara, et al. (2013). “Cellular concrete bricks with recycled expanded polystyrene aggregate.” Advances in Materials Science and Engineering 2013.
Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses), it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, which helps prevent moisture formation retaining its strength due to the greater adherence shown with dry polystyrene. It was more flexible, which makes it less vulnerable to cracking walls due to soil displacements. Furthermore, it is economical, because it uses recyclable material and has properties that prevent deterioration increasing its useful life. We recommend the use of the fully dry EP under a dry environment to obtain the best properties of brick. 2013 Juan Bosco Hernandez-Zaragoza et al.
Jitchaiyaphum, K., T. Sinsiri, et al. (2011). Cellular lightweight concrete containing pozzolan materials. 12th East Asia-Pacific Conference on Structural Engineering and Construction, EASEC12, January 26, 2011 – January 28, 2011, Hong Kong, Hong kong, Elsevier Ltd.
This research studies various properties of compressive strength, water absorption, and the porosity of cellular lightweight concrete or CLC, which is pre-formed foam method made from portland cement blended with foaming agent and pozzolan materials. Uses of fly ash replace cement in the proportions 10, 20 and 30 percent by weight of binder. Constant water to binder ratio of 0.5 and unit weight of 800 kg/m3 compared compressive strength at curing age 3, 14, 28 and 60 days. The study result that replacing cement with fly ash that is high strength on the early stage.
Kim, H. K., J. H. Jeon, et al. (2012). “Workability, and mechanical, acoustic and thermal properties of lightweight aggregate concrete with a high volume of entrained air.” Construction and Building Materials 29: 193-200.
This study investigated the various characteristics of lightweight aggregate concrete with a high volume of entrained air. The effects of lightweight aggregates and entrained air on the flow characteristics, density, porosity, compressive strength, and dynamic elastic modulus of the concrete were investigated. In addition, the acoustic transmission loss and thermal conductivity – essential performance measures for architectural construction materials – of lightweight aggregate concrete with a high volume of entrained air were measured. The lightweight aggregate cellular concrete containing an adequate amount of air entraining agent was shown to have excellent characteristics including very-high workability, low density and proper strength, and it can be applied in architectural members with high acoustic shielding and thermal insulating properties. 2011 Elsevier Ltd. All rights reserved.
Kloeker, W. (1982). LIGHTWEIGHT CONCRETE BASED ON CELLULAR UNSATURATED POLYESTER – TEN YEARS EXPERIENCE. Plastics in Material and Structural Engineering, Proceedings of the ICP/RILEM/IBK International Symposium., Prague, Czech, Elsevier Sci Publ Co.
Krivenko, P. V., G. Y. Kovalchuk, et al. (2005). Heat-resistant cellular concretes based on alkaline cements. 2005 International Congress – Global Construction: Ultimate Concrete Opportunities, July 5, 2005 – July 7, 2005, Dundee, Scotland, United kingdom, Thomas Telford Services Ltd.
Lightweight refractory materials traditionally used for heat insulation of high-temperature equipment can be successfully replaced with heat-resistant cellular (porous) concretes making for improving of technological process as well as of properties of masonry. However, some short-comings take place, such as application of expensive technologies, low mechanical properties under high temperatures, impossibility to obtain ultra low density etc. These problems can be solved by application of special alkaline cements which are heat-resistant owing to synthesis of thermostable microstructural compounds. The paper shows the possibility to obtain heat resistant cellular concretes based on two different binding systems represented by Geocements and alkaline portland cement. Cellular concretes elaborated have a density in the range of 300-1100 kg/m3, residual strength after firing up to 537% and thermal resistance up to 34 air cycles.
Latona, M. C., R. D. Neufeld, et al. (1996). Environmental impacts of autoclaved cellular concrete. Proceedings of the 1996 ASCE National Convention, November 10, 1996 – November 14, 1996, Washington, DC, USA, ASCE.
Autoclaved cellular concrete (ACC) is a lightweight building material with unique properties for application in interior and exterior construction. Fly ash ACC is created by mixing cement, lime, and foaming agent with reactive fly ash and water, and then curing in a steam autoclave. Crushed and whole block samples created from 10 different U.S. electric utility fly ashes were evaluated for heavy metal and trace organic leachates, MicrotoxR bioassays, and radon exhalation potentials. The results showed that the alkaline leachates exhibited equilibrium metal concentrations that were always below the regulatory threshold of 100 times applicable drinking water standard, and almost always less than ten times. The leachate concentrations did not consistently show a statistical correlation to crushed ACC particle size, nor did they correlate to concentrations of the same metal in the solid phase. A commercial bioassay procedure indicated no toxic effects due to leached metals. Organic analysis of solvent extracts indicated no release of hazardous PAHs attributable to the fly ash ingredient of ACC. Measured rates of radon exhalation were too low to cause potentially dangerous buildups in confined air spaces. Fly ash ACC is tentatively characterized as an environmentally green material, based on these findings.
Lee, H. K. and S. Y. Song (2010). “Influence of fiber volume fraction and fiber type on mechanical properties of FRLACC.” Journal of Reinforced Plastics and Composites 29(7): 1089-1098.
This article presents results of an experimental study conducted to investigate the influence of fiber volume fraction, fiber type, and presence of fly ash on mechanical properties of fiber-reinforced, lightweight aggregate, cellular concrete (FRLACC). Steel fibers are added at Vf of 0.5, 1.0, and 1.5%, and 25% of cement weight is replaced with fly ash in the control and FRLACC specimens that had shown the highest compressive strength in our preceding work. With the addition of 0.5% Vf of fibers, the increase in compressive strength of the polypropylene FRLACC specimens is slightly higher than that of the steel FRLACC specimens, whereas decreases in their peak load and modulus of rupture over those of control specimens are observed. The findings of the experimental study also show that the utilization of 25% fly ash is more efficient in improving the mechanical properties of the steel FRLACC specimens than those of the polypropylene FRLACC specimens. The Author(s), 2010.
Lee, H. K. and S. Y. Song (2010). “Performance characteristics of lightweight aggregate cellular concrete containing polypropylene fibers.” Journal of Reinforced Plastics and Composites 29(6): 883-898.
This article presents results of an experimental investigation conducted to determine the mix proportion and to characterize the corresponding engineering characteristics of a fiber-reinforced lightweight aggregate, cellular concrete (FRLACC) that was produced without autoclaves. A special foam agent was used to produce air bubbles in the cement matrix. A preliminary compression test was conducted to determine the mix proportion for FRLACC. A series of characterization tests on FRLACC specimens were then carried out to investigate engineering characteristics of FRLACC. The strength aspects of FRLACC were further evaluated by comparing the performance of FRLACC with that of other types of lightweight cellular concrete. It is shown that polypropylene fibers remarkably increase the compressive and splitting tensile strengths of lightweight cellular concrete, whereas the flexural strength of the lightweight cellular concrete is slightly decreased by adding the fibers. It is also shown that FRLACC has superior engineering characteristics in comparison with other types of lightweight cellular concrete. SAGE Publications 2010.
Lee, H. Y., S. Setunge, et al. (2011). Compressive strength and drying shrinkage of cellular lightweight concrete as affected by moisture content of the exposed environment. 21st Australasian Conference on the Mechanics of Structures and Materials, ACMSM21, December 7, 2010 – December 10, 2010, Melbourne, VIC, Australia, CRC Press.
Cellular lightweight concrete offers environmental benefits to construction sector with potential for reducing the self weight of concrete structures up to 50%. The material has superior insulation properties due to a porous microstructure. Current Australian standards do not cover cellular lightweight concretes, but guidance is required for this material. Due to the porous microstructure, the material is affected by the moisture content of the exposed environment. Work presented here examined the compressive strength and drying shrinkage of cellular lightweight concrete. It is observed that different exposure conditions change the compressive strength of this material by up to 22%. The magnitude of the change is less than expected possibly due to the dense skin which reduces the moisture exchange. Drying shrinkage of cellular lightweight concrete can be higher than that of normal weight concrete. However, the size effect on drying shrinkage is observed to be less pronounced compared to normal concrete. 2011 Taylor Francis Group, London.
Legatski, L. A. (1987). “INSULATING ROOF DECKS WITH CELLULAR CONCRETE.” Construction Specifier 40(11): 56-58, 61.
Cellular concrete is the most efficiently produced lightweight insulating concrete. By adding a predetermined volume of expansion material (preformed foam) to a cement/water slurry, the air cells are coated with cement paste and when hardened, preserve a discrete cell system within the matrix. Since cellular concretes have about the same water/cement ratio as regular concrete, their physical characteristics can be predicted, reproduced, and documented. Recognized by the American Concrete Institute (ACI) and the American Society of Testing and Materials (ASTM), cellular concretes follow standard testing procedures, have physical properties that correlate with accepted ACI formulas. The advantages of cellular insulating concrete are examined.
Legatski, L. A. (1987). STRUCTURAL CONSIDERATIONS OF CELLULAR CONCRETE. Materials and Member Behavior, Proceedings of the Sessions at Structures Congress ’87., Orlando, FL, USA, ASCE.
Although not normally considered to be a structural material, cellular concrete possesses characteristics which may result in its having structural applications in building and structural design. There are a number of physical properties, characteristics, and benefits that these materials bring to the structure. These include such things as improved seismic resistance, dead load reductions, improved fire resistance, and excellent thermal performance. Cellular concretes have been used successfully for many years as lightweight insulating concrete roof decks, sound conditioned floor fills, and geotechnical and load reducing fills.
Li, X., J.-Y. Hwang, et al. (2009). Production of autoclaved cellular concrete with aluminum salt cake residues. 2009 AIChE Annual Meeting, 09AIChE, November 8, 2009 – November 13, 2009, Nashville, TN, United states, American Institute of Chemical Engineers.
Aluminum is recycled through a smelting process. Salt of NaCl and KCl mixture was added during the smelting to seal the air from the aluminum melt and to help dissolving the surface aluminum oxide. After aluminum smelting, the salt cake is disposed. In this study, aluminum salt cake is processed to recover the salt and coarse aluminum particles. The residue powder is rich in aluminum oxide, but still containing a few percent of fine aluminum metal locked in the powder. Attempt is made to substitute the aluminum metal powder in the autoclaved cellular concrete production with the aluminum salt residue. Aluminum can react with water at high pH to generate hydrogen gas. This property has been utilized for the production of autoclaved cellular concrete, where aluminum powder is added to a mixture of cement, lime, water and sand to develop a foamed lightweight concrete structure. This material is lightweight and has good insulation property. However, the use of expensive aluminum powder has limited its broad applications. Results of this study indicated that this aluminum salt cake residue can generated a sufficient amount of H2 gas, and the product exhibits 50 pcf in density and 400 psi in strength. This research also indicates that the most efficient value of cement addition is 20 wt% for the autoclave processing.
Litsomboon, T., P. Nimityongskul, et al. (2009). “Development of lightweight aggregate concrete containing pulverized fly ash and bottom ash.” Key Engineering Materials 400-402: 379-384.
This study examines the feasibility of using different lightweight aggregates (LA) and bottom ash as coarse and fine aggregates in concrete with fly ash. The lightweight materials were composed of 3 types, namely pumice, cellular lightweight aggregate and MTEC lightweight aggregate. The tests for physical and mechanical properties of lightweight aggregate concretes (LWAC) were conducted in terms of workability, compressive strength, apparent density, abrasion resistance and absorption. Test results showed that compressive strength of LWAC increased with an increase in apparent density, which is mainly depending on the type of aggregate. The replacement of normal weight sand with bottom ash resulted in a decrease both in density of concrete by 180-225 kg/m3 and 28-day compressive strength of concrete by 16-26%. Moreover, the use of bottom ash to replace sand in concrete increased the demand for mixing water due to its porosity and shape and to further obtain the required workability. The type and absorption of LA influenced predominantly the water absorption of LWAC. Total replacement of natural sand by bottom ash increased the absorption of the concrete by 63-90%. With regard to abrasion resistance, the abrasion resistance of lightweight aggregate concrete was mainly dependent on the compressive strength of concrete: the higher the strength, the higher the abrasion resistance of LWAC. In addition, the use of bottom ash as a fine aggregate resulted in a lower abrasion resistance of lightweight aggregate concrete due to its porosity. Of the three types of lightweight materials, MTEC LA had achieved both low density and high compressive strength.
Mirza, W. H. and S. I. Al-Noury (1986). “UTILISATION OF SAUDI SANDS FOR AERATED CONCRETE PRODUCTION.” International journal of cement composites and lightweight concrete 8(2): 81-85.
This paper describes the utilization of potential sources of abundant sands available in many parts of the Western Province of the Kingdom of Saudi Arabia. Suitable gradings of sands from five different sources have been used in making aerated concrete by mixing with cement, lime and a foaming agent. Basic properties like density and compressive strength have been determined. The use of some common types of surface treatments has been investigated as an effective measure to reduce moisture penetration and to improve resistance against sulphate attack. The behavior of non-autoclaved and autoclaved aerated concrete has been observed to be different when subjected to sulfate attack or when exposed to very high temperatures.
Molnar, J. (1989). “Perlite mining in Hungary.” Mining Magazine 161(6): 498-499, 501.
Perlite is a glassy volcanic rock of rhyolitic composition whose unique properties arise from 2-3% combined water content. When granular perlite is heated to a temperature close to its softening temperature (850-900C), the contained water is converted to steam and the grains swell into light, snow white cellular particles. A volume increase of up to 20 times is common. Apart from its light weight, expanded perlite possesses excellent heat and sound insulation properties and is used as a lightweight insulating aggregate in concretes, plasters, boards, and as a loose fill in cavity walls and cryogenic vessels. It also finds important usage in filtration and horticultural applications.
Nemes, R. and Z. Jozsa (2004). Expanded glass pellets as an aggregate for lightweight concrete. 5th International PhD Symposium in Civil Engineering, June 16, 2004 – June 19, 2004, Delft, Netherlands, A.A. Balkema Publishers.
A new series of cellular pellet aggregate products made of waste glass are manufactured recently in Hungary. The products are tested to study their suitability for concrete technology. The most remarkable characteristic of these pellet products is their very low water absorbing capacity. Widespread laboratory test results are analysed in present paper covering compressive strength, failure modes, water absorption, density of LWAC. 2004 Taylor Francis Group, London.
Nurzynski, J. (2008). The effect of additional thermal lining on the acoustic performance of a wall. 7th European Conference on Noise Control 2008, EURONOISE 2008, June 29, 2008 – July 4, 2008, Paris, France, S. Hirzel Verlag GmbH.
External thermal insulation composite systems (ETICS) are commonly used in Poland for thermo-retrofitting of old multifamily buildings as well as for proper insulation of new buildings constructed presently. Blocks of flats built in sixties and seventies are the main group subjected to thermo modernization. Additional insulating layer radically improves thermal performance of a wall but at the same time reduces its sound insulation in a certain frequency range depending on the resonance frequency of the wall-lining system. Usually the acoustic effect of thermo retrofitting is unnoticed by inhabitants as windows decide on the total sound insulation of a building envelope. The problem becomes important in the case of noisy locations. The paper presents results of experimental investigation on the influence of lightweight linings on the acoustic performance of a massive wall. Different claddings, based on expanded polystyrene and mineral wool applied to basic walls made of calcium silicate blocks, cellular concrete and hollowed ceramics are considered. The effect of lining, its resonance frequency and influence on single number quantities is discussed as well as the problem of sound reduction index improvement prediction acc to EN 12354-1 and separate acoustical characteristics of a lining and testing acc. to ISO 140-16.
Panesar, D. K. (2013). “Cellular concrete properties and the effect of synthetic and protein foaming agents.” Construction and Building Materials 44: 575-584.
Cellular concrete consists of cement, water, aggregate and air voids. Cellular concrete can have between 10% and 70% air, which results in a material that is lightweight but may compromise the compressive strength and durability properties. Although it has been shown in the literature that less connected air voids yield a lower reduction in compressive strength, few studies have reported a detailed characterization of the microstructure of cellular concrete. It is critical to understand the impact of the microstructure and its implications on the development of strength, elastic modulus and transport properties in order to fully benefit from the lightweight properties, and this is the focus of this paper. Thirteen batches of cellular concrete were designed, prepared and tested. The air content varied, ranging from 6% to 35%. Three different foaming agents were used, one of which was protein-based and the other two were synthetic. Fresh properties such as slump, plastic air content and plastic density were measure for each batch of concrete as well as other properties, including hardened density, compressive strength, static elastic modulus, sorptivity, hardened air void distribution and thermal resistance. Key outcomes revealed that cellular concrete has good potential to be used for lightweight structural applications owing to its evolution of mechanical properties, transport properties and thermal resistance, but it is very sensitive to the type of foaming agent that is used. Outcomes showed that the foaming agent type had a noticeable effect on the thermal resistance and sorptivity coefficient but less of an effect on the mechanical properties. This is significant because the type of foaming agent used will directly influence the applications for which cellular concrete can be used. For example, cellular concrete designed with foaming agent B, which yields the greatest capillary pore volume is least suited for outdoor applications where the concrete may be exposed to moisture and or ions. 2013 Elsevier Ltd. All rights reserved.
Reichverger, Z. (1986). “USING AN IMPACT DEVICE WITH SLIDING DROP COLLAR FOR IN SITU EVALUATION OF COMPRESSIVE STRENGTH OF INSULATING CELLULAR CONCRETE.” Journal of Testing and Evaluation 14(6): 298-302.
This paper describes the efforts of the Central Building Laboratory of the Standards Institute of Israel to develop a relatively simple method for in situ nondestructive evaluation of the compressive strength of lightweight cellular concrete used for thermal insulation of roofs. The idea of the developed impact device with sliding drop collar is similar in principal to the well-known soil test method of drop-weight penetration, ordinarily used for field determination of compacted soil density. Test results show that the depth of penetration is influenced by two main parameters: compressive strength of the concrete and its density. If the unit weight of the cellular concrete is known or predetermined, its compressive strength can be estimated by means of the impact device with a sufficient degree of accuracy.
Tay, J. H. and W. K. Yip (1989). “Sludge ash as lightweight concrete material.” Journal of Environmental Engineering 115(1): 56-64.
Sludge is an inevitable by-product of wastewater treatment. Its abundance poses disposal problems that can be drastically reduced if sludge can be converted for economical uses in construction as substitute materials. Digested and dewatered sludge, after incineration at a high temperature, yields a hard, cellular porous mass with low unit weight. This hardened mass of sludge ash can be crushed to smaller-sized aggregates, which, when graded in suitable proportions, manifest the basic attributes required of lightweight aggregates. When used as aggregates in the production of lightweight concrete, experimental results show that the resulting concrete satisfies the physical requirements of a lightweight concrete in terms of unit weight, strength, heat-insulating properties, and fire resistance, thus indicating that sludge ash could be a potential source of suitable lightweight aggregates.
Tumova, E. and R. Drochytka (2013). Development of flooring materials with cellular waste. 14th International conference on rehabilitation and reconstruction of buildings, CRRB 2012, November 6, 2012 – November 7, 2012, Brno, Czech republic, Trans Tech Publications Ltd.
New building materials, additives, fillers, and secondary raw materials of various properties are being increasingly used in the development of floor structures. It is possible to develop new types of materials with different mechanical properties. Lightweight construction materials are the essential element for the industrial floors lightening and, thereby, for reducing their weight. This is especially beneficial for multi-story buildings. (2013) Trans Tech Publications, Switzerland.
Uddin, N., F. Fouad, et al. (2006). “Structural characterization of hybrid Fiber reinforced Polymer (FRP)-Autoclave Aerated Concrete (AAC) panels.” Journal of Reinforced Plastics and Composites 25(9): 981-999.
The structural characterization of hybrid fiber reinforced polymer (FRP)-autoclaved aerated concrete (AAC) panels is examined in this study. The structural system is based on the concept of a sandwich construction with strong and stiff FRP composite skins bonded to an inner AAC panel. The FRP composite material is made of carbon reinforcing fabrics embedded in an epoxy resin matrix. The carbon fiber reinforced polymer (CFRP) reinforcement is applied on the top and bottom faces of the AAC panel, and several innovative processing techniques are used including the hand lay-up as well as the vacuum assisted resin transfer molding (VARTM). The main focus of the research is to combine the AAC with the FRP face sheets into a synergetic system, which would be consistent with the recent interest in high performance and zero maintenance of civil infrastructures. This combination, being lightweight in nature, has the potential to be used for speedy panelized construction purposes, for disaster mitigation, and to prevent labor-intensive construction. The CFRP has been used with regular concrete before and has shown phenomenal reinforcing capabilities. The AAC, on the other hand, is a cellular concrete and is very light to work with, in comparison to normal concrete. It is also structurally very brittle in nature and has much lower flexural as well as compressive strengths than normal weight concrete. An experimental protocol based on a four point bending test is used to characterize the stiffness, ductility, and strength response of the hybrid FRP-AAC sandwich panels. Since there are no previous research data available on the hybrid CFRP-AAC panels and the bonding characteristics of AAC with FRP are unknown, a set of basic tests are also initiated including the bonding test on AAC samples wrapped with CFRP. To understand and optimize the flexural/shear behavior of the hybrid CFRP-AAC sandwich panels, several innovative reinforcing schemes with CFRP skin are used, as elaborated in this article. In addition, both continuous and discrete AAC blocks are used to fabricate AAC panels. Results from the experiments emphasize the need for a complementary test program where the best reinforcing scheme from the study would be duplicated in future tests on structural elements of the typical sizes including beams, floors, lintels, etc. 2006 SAGE Publications.
Velis, C. A., C. Franco-Salinas, et al. (2014). “Up-cycling waste glass to minimal water adsorption/absorption lightweight aggregate by rapid low temperature sintering: Optimization by dual process-mixture response surface methodology.” Environmental Science and Technology 48(13): 7527-7535.
Mixed color waste glass extracted from municipal solid waste is either not recycled, in which case it is an environmental and financial liability, or it is used in relatively low value applications such as normal weight aggregate. Here, we report on converting it into a novel glass-ceramic lightweight aggregate (LWA), potentially suitable for high added value applications in structural concrete (upcycling). The artificial LWA particles were formed by rapidly sintering (10 min) waste glass powder with clay mixes using sodium silicate as binder and borate salt as flux. Composition and processing were optimized using response surface methodology (RSM) modeling, and specifically (i) a combined process-mixture dual RSM, and (ii) multiobjective optimization functions. The optimization considered raw materials and energy costs. Mineralogical and physical transformations occur during sintering and a cellular vesicular glass-ceramic composite microstructure is formed, with strong correlations existing between bloating/shrinkage during sintering, density and water adsorption/absorption. The diametrical expansion could be effectively modeled via the RSM and controlled to meet a wide range of specifications; here we optimized for LWA structural concrete. The optimally designed LWA is sintered in comparatively low temperatures (825-835 C), thus potentially saving costs and lowering emissions; it had exceptionally low water adsorption/absorption (6.1-7.2% w/wd; optimization target: 1.5-7.5% w/wd); while remaining substantially lightweight (density: 1.24-1.28 g.cm-3; target: 0.9-1.3 g.cm-3). This is a considerable advancement for designing effective environmentally friendly lightweight concrete constructions, and boosting resource efficiency of waste glass flows. 2014 American Chemical Society.
Wei, S., Y. Yonggan, et al. (2014). Finite volume numerical analysis of the thermal property of cellular concrete based on two and three dimensional X-ray computerized tomography images. 4th International Conference on the Durability of Concrete Structures, ICDCS 2014, July 24, 2014 – July 26, 2014, West Lafayette, IN, United states, Purdue University.
Cellular concrete is one kind of lightweight concrete, which are widely used in thermal insulation engineering project. In this study, a three dimensional (2D and 3D) finite-volume-based models was developed for analyzing the heat transfer mechanisms through the porous structures of cellular concretes under steady-state heat transfer condition and also for investigating the differences between 2D and 3D modeling results. 2D and 3D reconstructed pore networks were generated from the microstructural information measured by a 3D image captured by X-ray computerized tomography (X-CT). In addition, the 3D-computed value of the effective thermal conductivity was found to be in better agreement with the measured value, in comparison with that computed on the basis of 2D cross-sectional images. Finally, the thermal conductivity computed for different porous 3D networks of cellular concretes were compared with those obtained from 2D computations, revealing the differences between 2D and 3D image-based modeling: a correlation was thus derived between the results computed with 3D and 2D models. 2014 4th International Conference on the Durability of Concrete Structures.