Preparation and characterization of high porosity cement-based foam material

Sang, Guochen; Zhu, Yiyun; Yang, Gang; Zhang, Haobo

doi:10.1016/j.conbuildmat.2015.05.032

Cited by 112 publications

(41 citation statements)

References 26 publications

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“…The incorporation of fine lightweight aggregate reduced the dry density, and as a consequence the thermal conductivity of the foamed concrete fell. Other researchers have also found a correlation between thermal conductivity and pore size distribution [38,39]. The connectivity of the pores, in addition to their size, can affect the thermal conductivity of concrete significantly.…”

Section: Thermal Conductivitymentioning

confidence: 90%

Preparation and Characterization of Ultra-Lightweight Foamed Concrete Incorporating Lightweight Aggregates

et al. 2019

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Increasing interest is nowadays being paid to improving the thermal insulation of buildings in order to save energy and reduce ecological problems. Foamed concrete has unique characteristics and considerable potential as a promising material in construction applications. It is produced with a wide range of dry densities, between 600 and 1600 kg/m3. However, at a low density below 500 kg/m3, it tends to be unstable in its fresh state while exhibiting high drying shrinkage in its hardened state. In this study, lightweight aggregate-foamed concrete mixtures were prepared by the addition of preformed foam to a cement paste and aggregate. The focus of the research is the influence of fly ash, as well as fine lightweight aggregate addition, on the properties of foamed concrete with a density lower than 500 kg/m3. Concrete properties, including stability and consistency in the fresh state as well as thermal conductivity and mechanical properties in the hardened state, were evaluated in this study. Scanning electron microscopy (SEM) was used to study the microstructure of the foamed concrete. Several mixes with the same density were prepared and tested. The experimental results showed that under the same bulk density, incorporation of fine lightweight aggregate has a significant role on compressive strength development, depending on the characteristics of the lightweight aggregate. However, thermal conductivity is primarily related to the dry density of foamed concrete and only secondarily related to the aggregate content. In addition, the use of fine lightweight aggregate significantly reduces the drying shrinkage of foamed concrete. The results achieved in this work indicate the important role of lightweight aggregate on the stability of low-density foamed concrete, in both fresh and hardened states.

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Section: Thermal Conductivitymentioning

confidence: 90%

Preparation and Characterization of Ultra-Lightweight Foamed Concrete Incorporating Lightweight Aggregates

et al. 2019

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“…(2) the CFA addition could improve the rheological property of geopolymer slurry and help to form the porous geopolymer blocks with more uniform porous structure [24], which may be beneficial to the mechanical strengths development [33,34].…”

Section: Physical Propertiesmentioning

confidence: 99%

“…In fact, the increase of porosity reduces the volume of the skeleton structure, and the thermal conductivity of it is much higher than which suggested that the mechanical strength usually decreases with the increase of porosity [26][27][28], the porosity increase of the GFs has not had a negative impact on the strength development in this investigation. This is mainly owing to the following two reasons: (1) the high pozzolanic activity of CFA would be helpful to improve the mechanical strengths of MK GFs [29][30][31][32]; (2) the CFA addition could improve the rheological property of geopolymer slurry and help to form the porous geopolymer blocks with more uniform porous structure [24], which may be beneficial to the mechanical strengths development [33,34].…”

Section: Thermal Conductivitymentioning

confidence: 99%

Fabrication and Fireproofing Performance of the Coal Fly Ash-Metakaolin-Based Geopolymer Foams

Peng

Qin

et al. 2020

Materials

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This paper aims to investigate the influence of coal fly ash (CFA) addition on the fireproof properties of the metakaolin-based geopolymer foams. The physical properties, thermal conductivity and fire resistance of the CFA-metakaolin-based geopolymer foams are discussed. The CFA-metakaolin-based geopolymer foams achieve a dry density between 259.43 kg/m 3 and 349.73 kg/m 3 , a porosity between 71.78% and 72.98%, a thermal conductivity between 0.0871 W/(m·K) and 0.0944 W/(m·K) and a compressive strength between 0.38 MPa and 0.56 MPa, exhibiting better physical properties than that of the porous blocks without CFA addition. It is also found that the CFA addition could decrease the viscous sintering temperature and change the phase compositions of sintering products, resulting in the porous structure deterioration in a certain extent and obvious rise of the final reverse-side temperature during the fire-resistance tests. Fortunately, the conversion of the amorphous geopolymer gel to ceramics has helped to maintain the main skeleton structure stability. The CFA-metakaolin-based geopolymer foams still exhibit excellent fire resistance, and the reverse-side temperatures are always within 250 • C after 3 h fire-resistance tests.

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“…This finding may be due to the gradual decrease in relative viscosity of cement paste as the w/c ratio increased, thus weakening the bubble-maintaining capacity of the paste. Small bubbles in the paste were easily combined and readily expanded during the stirring process [14]. Meanwhile, the frictional force in the paste reduced, rendering the bubbles increasingly round.…”

Section: Effect Of W/c Ratio On the Foam Concrete Pore Structurementioning

confidence: 99%

“…w/c ratio is an important factor that influences foam concrete performance [6][7][8][9][10][11]. Existing research on the effect of w/c ratio on the pore structure and performance of foam concrete mainly emphasizes high-porosity foam concrete (porosity > 85%) [12][13][14]. By contrast, few studies have discussed the influences of w/c ratio on the pore structure and performance of ordinary foam concrete (porosity < 85%) [15].…”

Section: Introductionmentioning

confidence: 99%

Effect of Water-Cement Ratio on Pore Structure and Strength of Foam Concrete

Liu

Zhao

et al. 2016

Advances in Materials Science and Engineering

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Foam concrete with different dry densities (400, 500, 600, 700, and 800 kg/m3) was prepared from ordinary Portland cement (P.O.42.5R) and vegetable protein foaming agent by adjusting the water-cement ratio through the physical foaming method. The performance of the cement paste adopted, as well as the structure and distribution of air pores, was characterized by a rheometer, scanning electron microscope, vacuum water saturation instrument, and image analysis software. Effects of the water-cement ratio on the relative viscosity of the cement paste, as well as pore structure and strength of the hardened foam concrete, were discussed. Results showed that water-cement ratio can influence the size, distribution, and connectivity of pores in foam concrete. The compressive strength of the foam concrete showed an inverted V-shaped variation law with the increase in water-cement ratio.

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Preparation and characterization of high porosity cement-based foam material

Cited by 112 publications

References 26 publications

Preparation and Characterization of Ultra-Lightweight Foamed Concrete Incorporating Lightweight Aggregates

Preparation and Characterization of Ultra-Lightweight Foamed Concrete Incorporating Lightweight Aggregates

Fabrication and Fireproofing Performance of the Coal Fly Ash-Metakaolin-Based Geopolymer Foams

Effect of Water-Cement Ratio on Pore Structure and Strength of Foam Concrete

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