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This study identifies admixtures to enhance the effectiveness of Sodium Lauryl Sulphate (SLS) as a foaming agent by increasing the foam density and stability. Sodium hydroxide, sodium carbonate and sodium chloride were chosen based on common ion effect to increase the viscosity of the foaming solution in order to achieve ASTM recommended range of f...
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... identifying the water content that will provide a mix with required consistency, the foam volume required to be added to achieve a fresh foam concrete density of 1200 kg/m 3 has been arrived at as per the method described in ASTM C 796 [5]. The fresh and hardened densities, 28 day compressive strength and water absorption of foam concrete presented in Table-6 indicate the effectiveness of these foaming agents. ...Similar publications
Society demands effective electromagnetic wave (EMW) absorbers that are lightweight, with a broad absorption band and strong absorption, to solve excessive electromagnetic radiation. Herein, ultralight magnetic graphite-like C3N4/carbon foam (MCMF) was fabricated via impregnating polymerized melamine formaldehyde (MF) foams in Fe3O4 nanoparticle so...
Foam glass is an innovative material is which composed of glass and carbon/carbonate based minerals; and has incomparable properties like lightweight, high thermal insulation and high porosity with sufficient mechanical strength. In the present study, the effects of the glass type and mineral addition on the foam glass properties were investigated....
Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthe...
Smoldering processes of flexible polyurethane foam (FPUF) with densities of 20.0, 30.0 and 35.0 kg/m³ were simulated in a self-designed mesoscale generator with dimensions of 60.0 cm × 25.0 cm × 25.0 cm. Characteristic parameters like smoldering establishment time, average smoldering rate, smoldering temperature, and high temperature duration were...
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Citations
... Foam concrete is cellular concrete produced with cement, sand, and foam generated using surfactants and water as ingredients. Adequate control of foam dosage can yield a wide range of densities, from 300 to 1800 kg/m 3 [15][16][17]. Surfactants (or foaming agents) play a vital role in foam generation and stabilization by reducing the surface tension of the water. ...
Extrudability is one of the most critical factors when designing three-dimensional printable foam concrete. The extrusion process likely affects the foam stability which necessitates the investigation into surfactant properties particularly for concrete mixes with high foam contents. Although many studies have been conducted on traditional foam concrete in this context, studies on three-dimensional printed foam concrete are scarce. To address this research gap, the effects of surfactant characteristics on the stability, extrudability, and buildability of three-dimensional printed foam concrete mixes with two design densities (1000 and 1300 kg/m3) using two different surfactants and stabilizers (synthetic-based sodium lauryl sulfate stabilized with carboxymethyl cellulose sodium salt, and natural-based hingot surfactant stabilized with xanthan gum) were investigated in this study. Fresh density tests were conducted before and after the extrusion to determine stability of the foam concrete. The results were then correlated with surfactant qualities, such as viscosity and surface tension, to understand the importance of key parameters in three-dimensional printing of foam concrete. Based on the experimental results, surfactant solu1tion with viscosity exceeding 5 m Pa·s and surface tension lower than 31 mN/m was recommended to yield stable three-dimensional printable foam concrete mixes. Nevertheless, the volume of foam in the mix significantly affected the printability characteristics. Unlike traditional foam concrete, the variation in the stabilizer concentration and density of concrete were found to have insignificant effect on the fresh-state-characteristics (slump, slump flow, and static yield stress) and air void microstructure of the stable mixes.
... I. S. Ranjani & Ramamurthy, 2010a, 2010b. The bubble coalesces as the foam production pressure rises, and the bubble then begins to deteriorate more quickly (Siva et al. 2015). Low pressure makes it difficult to produce foam since it doesn't fulfill the conditions needed for liquid to do so (Selija & Gandhi, 2022). ...
The commercially using synthetic surfactants have better foaming behavior at lower concentrations with the only drawback of forming a thin film wall around the foam bubbles. This leads to the rupture of foam by the attraction at the interface of bubbles and the air. Hence alternative anionic ammonium-based synthetic surfactants having the same hydrophilic head used for foam generation are investigated in this research. ALS and TLS are anionic synthetic surfactants having negatively charged Sulfate ion as their hydrophilic part and having a greater affinity towards the positively charged ions. The stability of TLS-foam increased up to 80% with a concentration of about 1.00 mol/L (M). The foam drainage test was performed to assess the characteristic behavior of the preformed foam. The regression model demonstrating the relationship between foam stability and various response parameters was examined using statistical analysis software. The results indicate that the surfactant concentration and foam expansion ratio significantly impact foam stability, as indicated by the regression equation's R² value, which is almost equal to 1.00.
... The drainage study was carried out for 30 minutes considering the nominal initial setting time of cement. 29 ...
Foam concrete has recently piqued the interest of defense engineering because of its innovative properties of absorbing energy, softening impact, exhausting oscillation, and lowering stress amplitude behavior. However, only a few investigations on foam concrete’s mechanistic behavior and energy absorption properties have been published. This study examines the effects of adding fly ash (sand replacement) and polypropylene fibers to foam concrete with design densities of 1,000 and 1,500 kg/m3 on fresh state features (stability and consistency), mechanical properties, and energy absorption capacities. The consistency of foam concrete increases with the addition of foam and fly ash, but the inclusion of fibers has a significant impact. Though the addition of fibers reduced the compressive strength of foam concrete, the bonding of fibers with the matrix is strengthened in fly ash–based mixes, resulting in increased strength, showing the synergistic effect. An improvised low-velocity drop-weight impact test is carried out on foam concrete target slabs produced with various mix compositions to investigate the impact mitigation properties of foam concrete under impact loading. The energy absorption capacity of different mixtures of foam concrete specimens is found to vary between 0.3 and 1.18 J using the conservation of energy law and assuming no energy losses. Because of the availability of sufficient bubble space for crushed debris and the better impact resistance provided by the fibers, mixes with more air and fibers displayed relatively more energy absorption. To examine the mixes based on the local area effect of impact loading, observations on both energy absorption and failure mechanism are carried out.
... Solids percentage was calculated as 58% from dried samples. A non-proprietary foam agent (FA) was prepared using mixtures and methods adapted from Siva et al. (2015). ...
Foamed plastic rigid insulation panels are effective for reducing building heating and cooling loads, with consequent reductions in energy use and associated greenhouse gas (GHG) emissions. However, plastic foam manufacturing and in-service use result in significant GHG emissions. In addition, plastic foams are flammable, and have been implicated in recent building fires. This paper describes proprietary mixtures and methods for producing drywall waste foam (DWF) panels, a carbon-neutral, fire-protective insulation made from gypsum drywall waste and other construction and demolition (C&D) waste materials. Gypsum drywall waste is inherently fire-protective and has relatively low thermal conductivity, but is a low-value commodity with few current reuse and recycling applications. DWF panels address two pressing issues in the built environment: decarbonization of building materials, and diversion of problematic C&D waste from landfills. Investigation of DWF panel engineering properties, including density, hardness, friability, burn-through time, and thermal conductivity are reported, with results compared to analogous commercially-available materials. Potential applications and areas for future investigation are also discussed.
... Solids percentage was calculated as 58% from dried samples. A non-proprietary foam agent (FA) was prepared using mixtures and methods adapted from Siva et al. (2015). ...
Foamed plastic rigid insulation panels are effective for reducing building heating and cooling loads, with consequent reductions in energy use and associated greenhouse gas (GHG) emissions. However, plastic foam manufacturing and in-service use result in significant GHG emissions. In addition, plastic foams are flammable, and have been implicated in recent building fires. This paper describes proprietary mixtures and methods for producing drywall waste foam (DWF) panels, a carbon-neutral, fire-protective insulation made from gypsum drywall waste and other construction and demolition (C&D) waste materials. Gypsum drywall waste is inherently fire-protective and has relatively low thermal conductivity, but is a low-value commodity with few current reuse and recycling applications. DWF panels address two pressing issues in the built environment: decarbonization of building materials, and diversion of problematic C&D waste from landfills. Investigation of DWF panel engineering properties, including density, hardness, friability, burn-through time, and thermal conductivity are reported, with results compared to analogous commercially-available materials. Potential applications and areas for future investigation are also discussed.
... Nanoparticles have been widely selected to stabilize foams for their utilization in flotation and oil recovery [14][15][16], whereas proteins have been used as admixtures in food and cosmetics to enhance their properties [17]. Similarly, biopolymers and inorganic salts have been used for fire extinguishing and foamed concrete production [18][19][20]. Foam stabilization by introducing multiple admixtures has recently been gaining attention to effectively utilizing different mechanisms contributed by the individual admixture and their interaction. Erasov et al. [21] found that the addition of sodium bentonite particles significantly enhanced the foam stabilizing ability of xanthan gum by forming a large number of floccules in the foam film, which prevented the fluid drainage. ...
... Xanthan gum , a biopolymer, utilizes its long chain structure for the molecular entanglement [25,26] and thus holds a surfactant solution for a longer duration. Ionic additives to foaming solution such as NaOH, NaCl, and Na 2 CO 3 have been reported to increase the solution viscosity by the Le-Chatelier"s principle [27], i.e. the presence of common ions (sodium) reduce the dissolution of SLS, thus increasing the density [19], and further stabilize foams by the formation of an electrostatic double layer in the lamella. The electrostatic double-layer leads to the shielding effect and thus prevents bubbles from coalescence [28]. ...
... Based on the literature [19], the maximum dosage of sodium-based admixture was limited to 8% by weight of water. The shear rate sweep experiment showed the Newtonian behavior of SLS solution admixed with sodium-based admixtures (refer to Fig. A.1 in the appendix). ...
Foam characteristics, including density, stability, and texture, influence the properties of end products like foamed concrete. The present work investigates the individual and combined influence of xanthan gum and low-cost sodium-based admixtures (NaOH, NaCl, and Na2CO3) on the viscosity of sodium lauryl sulfate (SLS) foaming solution and the foam characteristics. Where xanthan gum induced its characteristic pseudo-plastic behavior to the foaming solution, the addition of sodium-based admixtures did not affect the Newtonian behavior of the SLS solution. The addition of sodium-based admixtures elevated the critical turbidity and Krafft temperature of the surfactant solution. Xanthan gum substantially reduced the liquid drainage and improved stability to a great extent. However, the increment in foam density was more gradual with increasing xanthan gum dosage, following an increase in lamella thickness. Sodium-based admixtures significantly increased the density of foam while reducing the bubble sizes. Further, the SLS solution admixed with xanthan gum and sodium-based admixture resulted in foam with properties intermediate to the foams stabilized with individual admixtures. The resulting foam had a higher density and a smaller mean bubble size than unstabilized or xanthan gum stabilized foam. In contrast, the stability was more increased compared to unstabilized or sodium-based admixture stabilized foam.
... Les bétons de mousse ainsi obtenus auront une structure poreuse peu significative. D'un autre côté, une pression trop élevée génère une turbulence dans le mélangeur et donne une mousse instable présentant densité élevée [23] [24]. ...
L’utilisation de matériaux recyclés dans les bétons en remplacement du sable permet de répondre à un double enjeu : la nécessité de préserver la ressource naturelle menacée d’épuisement et la possibilité de régler la problématique de l’accumulation des déchets. L’étude, réalisée en partenariat avec le laboratoire de génie civil et géo-environnement, a pour objet d’évaluer l’effet de trois matériaux recyclés sur les propriétés du béton mousse en substitution au sable. Ces trois matériaux recyclés sont les sédiments marins issus du dragage, les mâchefers d’incinération des déchets ménagers, et la fibre de verre recyclée. Le choix s’est porté sur le béton mousse car il permet de réaliser des économies en énergie et en coût. En effet la présence de volumes d’air créés par la mousse, lui confère une faible densité, des propriétés d’isolation thermique et une bonne ouvrabilité. L’objectif attendu de ce travail est de déterminer comment les matériaux recyclés impactent les propriétés du béton mousse et de montrer s’ils peuvent constituer des alternatives intéressantes au sable. Pour cela, il a été choisi d’adopter une approche analytique consistant à étudier chaque élément séparément et à observer son effet sur les autres éléments. L’étude a été menée en deux temps : - une étude préalable des propriétés des matériaux et de leur interaction avec la mousse. - une analyse comparative des propriétés des bétons mousse dans laquelle le taux de substitution et la teneur en mousse ont été variés. L’effet des matériaux seul sur le mélange, l’effet de la mousse seule sur le mélange et enfin l’effet des matériaux sur le mélange avec mousse ont été étudiés.L’expérimentation a montré que les sédiments peuvent constituer d’une très bonne alternative au sable. Ils présentent en effet de bien meilleures performances mécaniques, une meilleure ouvrabilité, un meilleur rapport résistance/densité, et ce sans altération des propriétés d’isolation thermique, leur permettant une utilisation plus structurelle. Une modélisation des effets et une optimisation de la formulation ont été proposées. Les résultats des mâchefers se sont révélés concluants. Les bétons mousse obtenus ont présenté des propriétés variables selon le taux de substitution adopté. Cela a permis de conclure qu’ils pouvaient se substituer parfaitement au sable pour diverses applications. Il serait intéressant d’expérimenter un plus grand nombre de formulations de béton mousse à comme cela a été fait pour les sédiments. Les résultats sur la fibre de verre recyclé sont intéressants mais moins concluants que les sédiments et les mâchefers. Les bétons mousse obtenus sont plus légers et plus isolants pour des taux de substitution supérieurs à un certain seuil. Cependant les fibres ne semblent pas constituées un renfort et présenter de bénéfice mécanique.
... The high level of sulphates in the wastewater from Station 1 is indicative of high usage of detergents at the station which translates into a high pH. Sulphate is a common additive in detergents usually applied as Sodium Lauryl Sulphate which is used to enhance foam density (Schliemann et al., 2014;Siva et al., 2015). When released into waterways, this can contribute to foaming (Richards, 2003;Vinod Dubey et al., Pandey, 2012) and together with Phosphorus and Nitrogen fuel eutrophication of waterbodies (Dodds and Smith, 2016;Pattusamy et al., 2013). ...
Carwash stations use large volumes of water and release harmful chemicals into the environment through their operations. While a significant body of literature has focused on exploring water use in the carwash industry, none has provided comprehensive information on both the pollution loads of the wastewater emanating from this industry and water consumption. Understanding how much water is used and the pollution loads of wastewater from this industry is useful to ensure adoption of water conservation measures and design wastewater recycling systems given the dwindling freshwater resources globally. This study estimated the freshwater quantities used to wash different vehicle types and the pollution loads of the resulting wastewater in the Kumasi Metropolis. Seven proxy carwash stations were purposively selected and monitored to estimate the water used to wash six different categories of vehicles. Composite wastewater samples from three carwash stations were analysed for concentrations of different contaminants which were used to compute pollution loads. Using R software, one-way ANOVA with Tukey's (HSD) post-hoc testing and 2-sample t-test at 95% confidence interval were employed to test statistical differences. After an 8-week monitoring campaign involving 3,667 vehicles, the study showed that average water used for each vehicle type were in the order: Motorbike - 97L (95% CI: 90–103L); Salon car - 158L (95% CI: 154–161L); SUV - 197L (95% CI:191–203L); Buses/Coaches - 370L (95%CI:351–381L); Articulated truck 1,139L (95% CI:916–1,363L); Graders/Loaders - 1405L (95% CI:327–2,483L). Overall, the carwash industry in the Metropolis uses about 1000m³ of freshwater daily and discharges the resulting wastewater into waterways untreated. The wastewater has a low Biodegradability Index (0.3–0.4) and is characterized by a mildly alkali pH (7.6–8.6) with high levels of Sulphates (40.8–69.8 mg/L), COD (990–1413 mg/L), TSS (1260–3417 mg/L) and E. coli (2.3–4.7 × 10³ CFU/100mL). Pollution loads of BOD and COD were up to 2tons/year and 6tons/year respectively. Stipulated effluent discharge guideline values were mostly exceeded – in some cases by up to 68 times. To avert the unbridled wastage of freshwater, the study recommends enforcement of wastewater recycling for all carwash stations and promulgation of a tax system that rewards stations that recycle wastewater and surchages those wasting freshwater.
... Foam cement has interested several experts because of its low density, low thermal conductivity, low permeability, high expansibility, and high strength [14]. Ivanov et al. [15] and Siva et al. [16,17] investigated the foaming properties of different types of foaming agents such as sodium lauryl sulphate. Deng et al. [18] and Fan et al. [19] studied the influencing factors of foam stability. ...
If an airtight wall in a coal mine leaks air, it may cause spontaneous combustion of residual coal in the gob and even cause a full-blown fire or gas explosion. In this study, we developed a new type of foamed concrete, low-alkalinity sulphoaluminate cement (LASC), to control air leakage. The performance of filling materials that were prepared by adding various dosages of foam to LASC was studied. The longer the curing period for the foam filling material of LASC, the better the crystallinity of the hydrated product. With an increasing foam dosage, the initial setting time gradually extends while the fluidity of the foam slurry decreases. The bubble rate of the filling material increases and the density decreases with increasing foam dosage. The compressive strength of the LASC filling material decreases with increasing foam dosage and increases with increasing curing time. In the LASC filling materials, the optimal volume ratio of foam dosage to gel slurry is 2. The crystallinity, initial gel time, and compressive strength of the LASC foaming materials are better than those of ordinary Portland cement (OPC) foaming materials. When the crossheading is filled with LASC foam cement, the deformation of the surrounding rock is less than 19 cm, and the air leakage prevention is better than that achieved with loess and fly-ash-cement foam. Thus, the proposed LASC foam material can be applied to the filling of the crossheading to efficiently prevent leakage in underground coal mines.
... As one of the core technologies of foamed concrete production, the stability of foam refers to the ability of foam liquid film to maintain independence without breaking, which is closely related with the performance, quality and yield of foamed concrete [28][29][30]. In order to solve the defect of poor stability of the anionic surfactant foaming agent foam, a foam stabilizer is widely applied to extend the foam life and improve the foam stability. ...
The stability of foam plays a vital role in the quality of foamed concrete. In this paper, foamed concrete with dry density of 600 kg/m³ and water-cement ratio of 0.5 had been fabricated by a commercially available anionic surfactant foaming agent with the xanthan gum as a foam stabilizer. Some essential tests were performed, like the surface tension, the foaming multiple, the bleeding rate, the compressive strength, and the water absorption test. In addition, the microstructure of fresh foam and the pore size distribution of the foamed concrete were analysed through optical microscope and scanning electron microscope (SEM), respectively.
