Analyzing the mechanical and material characteristics of cellular lightweight foam concrete and optimizing design mix through linear regression analysis

Abstract

This paper explores the use of novel lightweight concrete as an alternative material, focusing on Cellular Lightweight Foam Concrete (CLFC), renowned for its strength, low weight, thermal insulation, and sustainability. The study encompasses a thorough review of literature focusing on the evolution of lightweight concrete, experimental investigation including mix design variations and mechanical property analysis, statistical analysis using MINITAB software, SEM and EDS interpretation, and construction of model POD. Regression analysis was performed to investigate on the factors influencing compressive strength, revealing significant predictors such as cement, fly ash, water, and density, paving the way for enhanced concrete mixes. Characterization studies such as SEM and EDS were performed to analyse the formation of elements that contribute to the strength parameter. Moreover, the study underscores the potential of utilizing steam curing cycle to achieve early compressive strength in concrete mixes. Ultimately, the research aims to revolutionize construction practices by advocating for the widespread adoption of CLFC and innovative construction techniques to meet the demands of low-cost, eco-friendly housing.

Keywords:
SEM; Regression analysis; Sustainable; Affordable; Cellular Lightweight Foam Concrete (CLFC)

1. INTRODUCTION

The developed industrial countries first investigated and adopted composite structures in the early twentieth century. Industries worldwide are seeking solutions to enhance productivity in site construction, with primary focus on maintaining high-quality work while reducing costs. A novel lightweight concrete as a superior alternative material had been proposed for the construction of structural elements such as floor slabs, roof slabs and wall panels, to reduce their self-weight. This reduction in self-weight led to less material usage. Hence, requirements for foundation and transportation cost were reduced significantly. It allowed rapid and easy construction practices and paved way for mass production thereby saving in time and ultimately economy was achieved. The dominating factor affecting infrastructure development around the world is the high cost of conventional construction materials. This led to investigations on alternate construction materials.

One such superior alternative material is the Cellular Lightweight Foam Concrete (CLFC). It is a revolutionary material in the construction industry, known for its unique combination of strength, low weight, thermal insulation, and sustainability. The key characteristic of CLFC is its cellular structure, which is filled with numerous tiny air bubbles. These air bubbles significantly reduce the concrete’s density, resulting in a lightweight material that weighs considerably less than traditional concrete. It offers excellent thermal insulation, making it suitable for both hot and cold climates, as it helps maintain comfortable indoor temperatures and reduces energy consumption. Additionally, its sound-absorbing properties contribute to improved acoustic comfort within buildings. Another advantage of CLFC is its fire-resistant nature. The trapped air bubbles in the concrete act as a barrier against heat transfer, providing added fire protection to structures. This feature enhances safety and allows occupants more time to evacuate in the event of a fire. It utilizes a lower volume of raw materials, including cement, which is a significant contributor to carbon emissions during traditional concrete production.

In summary, CLFC offers a myriad of benefits, including reduced weight, excellent thermal and acoustic insulation, fire resistance, versatility, and sustainable attributes. Its widespread applications in building and construction projects continue to make it an attractive alternative to conventional concrete, leading to more energy-efficient, durable, and environmentally friendly structures. As research and technology advance, CLFC is likely to play an increasingly important role in the future of sustainable construction.

2. REVIEW OF LITERATURES

Literatures were studied to understand the performance of light weight concrete and also to gain knowledge about the evolution of light weight concrete as a replacement for conventional construction material. Initially light weight concrete was achieved by replacement with light weight aggregates and fibres incorporation. YASAR et al. [¹] conducted experiments investigating the efficacy of structural lightweight concrete (SLWC) utilizing basaltic pumice (scoria) as aggregate along with fly ash. The findings demonstrated a clear advantage in weight reduction. HOSSAIN [²] conducted a study focusing on volcanic pumice, examining its properties in concrete mixes where cement content ranged from 0% to 25% by weight, and coarse aggregate replacement varied from 0% to 100% by volume. The investigation evaluated the characteristics of Volcanic Pumice Concrete (VPC) based on Volcanic Pumice Aggregate (VPA), encompassing tests for workability, strength, drying shrinkage, surface absorption, and water permeability. BANTHIA [³] enhanced the compressive strength of concrete by adding deformed steel fibres. PARHIZKAR et al. [⁴] conducted experiments investigating the characteristics of lightweight concrete made with volcanic pumice aggregates. The findings of this research indicate that based on parameters like tensile strength and drying shrinkage, these lightweight concrete formulations satisfy the necessary standards.

After successful attainment of light weight concrete with replacements by aggregates and fibres, the evolution of Cellular Lightweight Concrete (CLC) began. SAGAR DHENGARE et al. [⁵] discussed about the properties of Cellular Lightweight Concrete such as Compressive strength, Drying Shrinkage, Consistency, Split Tensile Strength, Fire and Thermal Insulation. JITCHAIYAPHUM et al. [⁶] studied the material characteristics with the help of SEM images. The SEM results showed the distribution of bubbles formed by foam; CLC with low contents showed uniform distribution of bubbles whereas CLC with high contents showed cluster of irregular distribution of bubbles. Also, from the images it was identified that with increase in fly ash quantity in CLC, the size of pores decreased thereby increase in strength was achieved. ABDOLLAHNEJAD et al. [⁷] investigated on the joint effect of different mix parameters on the properties of foam, geopolymer and fly ash-based to produce sustainable and cost effective construction material.

CLC blocks were casted and studied to understand its performance as CLC evolved as a suitable alternative to conventional material in terms of low cost and sustainability. DEEPA et al. [⁸] examined the durability of aerated lightweight concrete blocks. By employing fly ash-based Cellular Lightweight Concrete, they significantly decreased the density compared to traditional concrete, while maintaining strength through appropriate design mixing. The study concluded that the production process for this concrete variant does not require expensive techniques, resembling conventional methods. Anik GUPTA and RATHORE [⁹] discussed about CLC being remarkably eco friendly as the casting of CLC blocks does not deplete the top soil and also does not release any harmful effluents to ground, water or air. The authors discussed on how the size of air voids affects the thermal insulation properties; smaller the size, less than 2 mm there was consequent increase in thermal insulation. The various advantages of CLC such as easy handling, thermal insulation, reduction in dead load thereby savings in transportation cost were discussed briefly. Also the test results showed a decrease in the rate of water absorption with increase in density of CLC. A comparative study between CLC blocks and conventional bricks showed almost 10% savings in steel reinforcement by using CLC.

Further investigations were conducted on CLC with various substitutes to enhance strength and performance under various conditions. CHANDEL and SAKALE [¹⁰] compared the performance of CLFC with replacement of cement by quarry dust and fly ash. The results proved that replacement of cement by fly ash served better than quarry dust. Compressive strengths and water absorption rate test results also proved that CLFC with fly ash performed better. In a study conducted by GOPALAKRISHNAN et al. [¹¹] the mechanical properties of fly ash and quarry dust based light weight foam concrete were assessed. They found that the concrete exhibited satisfactory compressive strength, making them suitable for non load-bearing applications. HUANG et al. [¹²] demonstrated that Ultra-Lightweight Cement Composite (ULCC) incorporating fly ash cenospheres achieved a low density within the range of 1250 to 1550 kg/m³. Additionally, they observed exceptional mechanical properties, including a compressive strength of up to 87.3 MPa, a flexural strength of 11.4 MPa, and exhibited deflection hardening behavior with minimal steel fiber content (0.5% by volume). This composite had found application in various structural elements such as steel-concrete-steel sandwich composite beams, walls, and shells, particularly in marine offshore environments. FU et al. [¹³] reviewed the properties of foam material that has impacts on strength and enhancement.

Cellular concrete finds diverse applications in the construction industry, as highlighted in the study by CHICA and ALZATE [¹⁴]. Their research investigated on the viability of utilizing durable concrete with novel combinations of ingredients in varying proportions, resulting in significantly improved specifications and performance. Their examination revealed that the pursuit of superior foaming agents and stabilizers, along with the production of geopolymeric cellular concretes, were emerging priorities in the research and implementation of foamed cellular concretes. KAMRUL HASSAN [¹⁵] undertook an experimental investigation into prefabricated lightweight wall panels subjected to flexural loading. The author suggested utilizing steel studs/angles instead of reinforcement bars, as they possess a higher moment of inertia compared to reinforcement bars, consequently enhancing the flexural strength of the wall panel. ASHRAFIAN et al. [¹⁶] investigated the potential of creating an integrative AI model by combining a standalone AI model with a nature-inspired optimization algorithm to predict the compressive strength (f_c) of FCLC. They validated the performance of this proposed model against established predictive models, including linear models (e.g., MLR) and non-linear models (e.g., ANN, SVR, MARS), for f_c prediction. The effect of lightweight concrete walls composed of identical blocks on blast wave pressure reduction in a tunnel was investigated by MOHAMMADI et al. [¹⁷]. The authors performed computational analysis to evaluate the performance of the walls.

Latest research by BHATT et al. [¹⁸] emphasized that the manufacturing process of CLC panels was critical to achieve the desired properties. They investigated different CLC mix designs and concluded that varying foam content, cement-to-foam ratio, and curing techniques significantly influence the panels’ density, strength, and durability. Proper control of the manufacturing process was essential to ensure consistent and reliable results.

SUBRAMANI and GANESAN [¹⁹] have studied the effect of graphene oxide and coloidalnano-silica on the microstructure and strength properties of fly ash blended cement composites for cost effective.

Based on the literature review, it is evident that the manufacturing process of Cellular Lightweight Foam Concrete (CLFC) panels plays a pivotal role in achieving desired properties and also investigations on CLC wall panels subjected to axial compressive loading is nil. Consequently, this research is directed towards enhancing the strength and durability of CLFC panels by incorporating different mix designs, additives, reinforcements, and curing methods, thereby making them suitable for load-bearing applications. This initiative aims to provide faster construction and reduced maintenance costs by incorporating new and innovative applications of CLFC panels, such as in architectural elements and prefabricated structures.

3. MATERIALS

The constituents of CLFC material are cement, fly ash, water, foaming agent and super plasticizer. OPC of Grade 53 and Fly ash of Class F were considered and their components by weight percentage were found by EDX studies are presented in the Table 1. The foaming agent named Genfil which is an animal fat based protein was considered in this study along with the super plasticizer, Master Glennium.

Table 1
Chemical composition of cement and fly ash.

COMPONENTS (wt, %)	CEMENT GRADE 53	FLY ASH CLASS F
Silica	20.1	54.3
Calcium oxide	63.2	2.75
Alumina	5.8	26.23
Ferric oxide	2.75	9.4
Magnesium oxide	1.5	–
Sulphuric anhydride	2.8	0.31
Titanium dioxide	0.39	–
Potassium oxide	1.04	3.704
Sodium oxide	0.09	0.6
Chlorine	0.01	0.006
Loss on ignition	2.32	2.7

4. EXPERIMENTAL INVESTIGATION

4.1. Mix design

ASTM C 869 [²⁰], ASTM C 796 [²¹] and ASTM C 495 [²²] specifications were used for formulating different mix designs further the variation level of mix parameters such as cement, fly ash, w/p, foam and super plasticizer is selected based on the mix proportions arrived theoretically as per EFNARC [²³,²⁴] guidelines. Mix proportions along with the compressive strength of the samples considered are presented in Table 2.

Table 2
Mix proportions and compressive strength of CLFC.

ID	CEMENT kg	FLY ASH kg	WATER kg	DENSITY kg/m3	MIX RATIO	COMP @ 28 kg/m3
S1	330	700	320	1170	1: 2.12: 0.97	7.92
	330	700	320	1170		9.17
	330	700	320	1170		8.54
S2	330	700	350	1120	1: 2.12: 1.06	7.34
	330	700	350	1120		8.48
	330	700	350	1120		6.98
S3	330	800	320	1250	1: 2.42: 0.97	11.78
	330	800	320	1250		10.42
	330	800	320	1250		11.08
S4	330	800	480	1080	1: 2.42: 1.45	6.32
	330	800	480	1080		6.82
	330	800	480	1080		7.16
S5	400	800	330	1240	1: 2: 0.83	10.25
	400	800	330	1240		9.97
	400	800	330	1240		11.54
S6	400	800	320	1245	1: 2: 0.8	10.53
	400	800	320	1245		10.78
	400	800	320	1245		11.32
S7	400	800	480	1060	1: 2: 1.2	6.07
	400	800	480	1060		6.42
	400	800	480	1060		5.08
S8	400	800	360	1230	1: 2: 0.9	9.42
	400	800	360	1230		9.16
	400	800	360	1230		10.78
S9	500	700	360	1090	1: 1.4: 0.72	6.46
	500	700	360	1090		6.72
	500	700	360	1090		7.18
S10	500	800	480	1010	1: 1.6: 0.96	5.72
	500	800	480	1010		5.82
	500	800	480	1010		6.42
S11	500	800	320	1240	1: 1.6: 0.64	10.18
	500	800	320	1240		9.94
	500	800	320	1240		11.42
S12	500	800	350	1230	1: 1.6: 0.70	9.35
	500	800	350	1230		9.74
	500	800	350	1230		10.12
S13	500	1060	440	1300	1: 2.12: 0.88	14.6
	500	1060	440	1300		14.92
	500	1060	440	1300		14.48
S14	500	1060	515	1260	1: 2.12: 1.03	11.5
	500	1060	515	1260		11.86
	500	1060	515	1260		12.32
S15	600	800	360	1160	1: 1.33: 0.6	9.72
	600	800	360	1160		9.98
	600	800	360	1160		9.54
S16	600	800	350	1200	1: 1.33: 0.58	9.996
	600	800	350	1200		9.76
	600	800	350	1200		10.32
S17	600	800	480	950	1: 1.33: 0.8	4.37
	600	800	480	950		4.88
	600	800	480	950		4.52
S18	600	1280	530	1540	1: 2.13: 0.88	17.5
	600	1280	530	1540		17.82
	600	1280	530	1540		17.34
S19	600	1280	620	1310	1: 2.13: 1.03	14.98
	600	1280	620	1310		14.32
	600	1280	620	1310		12.78
S20	300	400	230	900	1: 1.33: 0.77	2.97
	300	400	230	900		3.23
	300	400	230	900		3.86
S21	275	365	210	850	1: 1.33: 0.76	2.7
	275	365	210	850		2.98
	275	365	210	850		2.56
S22	225	300	175	775	1: 1.33: 0.78	2.15
	225	300	175	775		2.52
	225	300	175	775		2.98
S23	250	330	190	825	1: 1.32: 0.76	2.43
	250	330	190	825		2.62
	250	330	190	825		2.23

To find the optimal design mix, about 23 design mixes of varying cement, fly ash and water were analysed by keeping the admixture and foaming agent as constant. For every design mix, 3 samples were casted. In order to achieve high compressive strength at low density, the ratio of foaming agent to water was maintained at 1:50. The super plasticiser was used in the range of 1000 ml of Master Glennium for every cubic meter of CLFC.

4.2. Compressive strength

A total of 69 samples were tested to find the compressive strength at 28 days. Density of the samples ranging from 700–1600 kg/m³ was analyzed. The sample S22 with a density of 775 kg/m³ exhibited an average compressive strength of about 2.55 MPa whereas the sample S18 with a density of 1540 kg/m³ exhibited an average compressive strength of about 17.55 MPa. This variation in strength was due to the reduction in distribution of voids in the higher density sample. Although sample S18 exhibited higher compressive strength in order to achieve the aim of the study, the samples having density ranging from 1200 kg/m³ to 1300 kg/m³ were only chosen, to reduce the transportation cost. This variation of strength was due to increase in density and also the extent of completion of hydration process.

Graphs were plotted to understand the influence of density, fly ash/cement, water content/powder, water content/cement on compressive strength. Figure 1(a) shows that as density increases, the compressive strength also increases. On the other hand, Figure 1(b) indicates that with an increase in fly ash and a subsequent decrease in cement content, compressive strength increases. Additionally, it highlights that the optimal F/C ratio for maximum compressive strength of 10 N/mm² is 1.8. The density corresponding to this compressive strength, as derived from Figure 1(a) is 1220 kg/m³. Meanwhile, Figure 1(c) and 1(d) depict that the optimal values of W/P and W/C ratios for achieving a compressive strength of 10 N/mm² are 0.27 and 0.75 respectively. The desired ratios for the variables cement, fly ash, and water content were derived from the optimal values obtained from the graph. Consequently, the desired ratio entails requiring 1.8 times the quantity of fly ash for every 1 part of cement, along with 0.75 times the water content.

Figure 1
(a) Compressive strength vs density, (b) compressive strength vs fly ash to cement ratio, (c) compressive strength vs water to powder ratio and (d) compressive strength vs water to cement ratio.

4.3. Mechanical properties

To further understand the behavior of CLFC material, mechanical properties such as Modulus of Elasticity, Split Tension and Modulus of Rupture were investigated. Three cylinders fitted with compressometer were tested under compression to find the Modulus of Elasticity and the average stress-strain curve was plotted as shown in Figure 2. Additionally, 3 cylinders and 3 beams were casted to conduct Split Tensile test and Modulus of Rupture respectively. The beams were subjected to three point loading and the test results are tabulated in Table 3.

Figure 2
Stress vs strain curve.

Table 3
Mechanical properties.

MIX C: F: W	AVG. COMP. STRESS N/mm2	MODULUS OF ELASTICITY N/mm2	SPLIT TENSILE STRESS N/mm2	MODULUS OF RUPTURE N/mm2
1: 1.8: 0.75	10.85	9260	1.58	2.02

4.4. Statistical analysis for the design of mix

Statistical analysis was performed using MINITAB software. A total number of 69 observations were considered for the test. The predictor variables considered were cement, fly ash, water and density and the response variable was compressive strength. Linear Regression analysis was performed to fit a regression model to investigate the relationship between predictor variables and the response variable. Using the Minitab’s built-in ANOVA analysis tool the sum of squares, degrees of freedom, mean squares, F-statistic, and p-value for each factor and interaction term in the model were calculated. A regression equation is obtained by performing the linear regression analysis based on predictor and response variables assigned.

$$\text{Compressive Strength}=-2.08-0.00229\text{Cement}+0.02394\text{Fly}\text{Ash}-0.02774\text{Water}+0.00313\text{Density}$$(1)

External validation and further analysis were carried out to confirm the robustness and generalizability of the model. The results from the regression analysis are presented in Tables 4, 5 and 6 and Figure 3. The validation of the analytical model is illustrated in Table 7 and Figure 4.

Table 4
Coefficients.

TERM	COEF	SE COEF	t-VALUE	p-VALUE	VIF
Constant	–2.08	1.65	–1.26	0.215	–
Cement	–0.00229	0.00121	–1.89	0.066	3.15
Fly Ash	0.02394	0.00292	8.2	0	80
Water	–0.02774	0.00338	–8.21	0	22.62
Density	0.00313	0.00218	1.44	0.158	22.8

• Coefficient (COEF), Standard Error of Coefficient (SE COEF), Variance Inflation Factor (VIF).

Table 5
Model summary.

S	R-SQ	R-SQ (ADJ)	R-SQ (PRED)	TEST S	TEST R-SQ
0.59325	98.06%	97.87%	97.44%	0.546784	97.54%

• Root Mean Square Error (S), R-squared (R-SQ), Adjusted R-squared (R-SQ(ADJ)), Predicted R-squared (R-SQ(PRED)).

Table 6
Analysis of variance (ANOVA).

SOURCE	DF	ADJ SS	ADJ MS	F-VALUE	P-VALUE
Regression	4	763.018	190.754	542	0
Cement	1	1.256	1.256	3.57	0.066
Fly Ash	1	23.689	23.689	67.31	0
Water	1	23.712	23.712	67.38	0
Density	1	0.726	0.726	2.06	0.158
Error	43	15.134	0.352	–	–
Lack-of-Fit	17	4.728	0.278	0.69	0.78
Pure Error	26	10.405	0.4	–	–
Total	47	778.152

• Degrees of Freedom (DF), Adjusted Sum of Squares (Adj SS), Adjusted Mean Square (Adj MS).

Figure 3
Residual plots for compressive strength at 28 days.

Table 7
Validation.

VARIABLE	CEMENT kg	FLY ASH kg	WATER lit	DENSITY kg/m3	EXPERIMENTAL N/mm2	PREDICTED N/mm2
Setting 1 [8]	316	422	243	1000	3.12	3.53
Setting 2 [8]	269	358	206	900	2.78	2.91

Figure 4
Sample ID vs Avg. Comp. Strength.

4.5. SEM and EDS interpretation

To achieve early strength gain, steam curing was suggested through material characterization studies. To find the best practice, 3 samples obtained by adopting the desired design mix were considered. They were designated as CC-1; conventional curing, SC-1; steam curing cycle for a period of 8 hrs/day continued for 3 days and SC-2; steam curing for 24 hrs. To find the satisfactory steam curing period, two cycles were adopted. The sample SC-1, after casting was allowed to cure at room temperature until next day followed by the application of heating at the rate of 20°C per hour which was continued until the desired temperature of 70°C–80°C was attained. The samples were maintained at this temperature for 8 hrs followed by slower rate of cooling. This cycle was followed for 3 days. For the second type of steam curing cycle, the sample SC-2 was cured for a continuous period of 24 hrs whereas the sample CC-1 was cured at room temperature in the regular conventional way for 28 days.

The SEM images of the samples considered are presented in the Figures 5, 6 and 7 under different magnifications. The SEM images clearly show the formation of hydration products. The samples are also studied using Energy-dispersive X-ray spectroscopy (EDS) to know about the extent of free ions present and presented in the Figure 8(a), 8(b) and 8(c).

Figure 5
The SEM images of sample SC-1 under different magnifications.

Figure 6
The SEM images of sample SC-2 under different magnifications.

Figure 7
The SEM images of sample CC-1 under different magnifications.

Figure 8
EDS patterns of (a) SC-1, (b) SC-2 and (c) CC-1.

4.6. Model POD

The objective of the study is to produce low cost housing using eco-friendly material with an aim of replacing brick masonary. Generally the compressive strength of brick masonary ranges from 3.5 MPa to 17 MPa with the unit compressive strength of first class brick being 10 MPa. From our investigations on Cellular Lightweight Foam Concrete we achieved a compressive strength of 10 MPa which led to the replacement of brick masonary. Hence using this new material a model pod of size 10' × 10' × 10' was constructed in two ways to study its performance. Figure 9 shows the construction of model POD using MIVAN Technology and Figure 10 shows the conventional precast construction of the model pod.

Figure 9
Construction of model POD using MIVAN technology.

Figure 10
Precast construction of model POD.

The pods were constructed with 100 mm thick CLFC walls reinforced with 8 mm dia bars at 100 mm c/c on both ways. Composite slabs of thickness 150 mm consisting of two layers, one being CLFC at the bottom layer (tension zone) and the other layer was concrete of grade 20 MPa at the top layer with 8 mm dia bars at 150 mm c/c on both ways at the interface of two layers were considered for roof and floor.

5. DISCUSSION

From the regression analysis, it is inferred that the p-values for fly ash and water are both very close to zero thus indicating that fly ash and water are likely to have a significant impact on the response variable. However, cement’s coefficient has a relatively higher p-value, suggesting it may not be as significant. The F-value of 542 with a p-value of 0 obtained from ANOVA suggests that the regression model is statistically significant. Additionally, the individual predictor variables (cement, fly ash, water, density) all have very low p-values, indicating that each of them contributes significantly to explaining the variability in the response variable. The predicted R-squared value is 97.44% which indicates that the model has a good fit to the data and can effectively explain the observed variation in the response variable. High R-squared values and significant F-tests are desirable.

The results obtained from SEM and EDS were studied and compared. Crystalline structures found in samples SC-1 (Figure 5) and CC-1 (Figure 7) indicated the formation of C-S-H gel which contributes to the strength properties whereas sample SC-2 (Figure 6) was found to be amorphous in nature. The main elements that affect the hydration process are free silica and Ca(OH)₂ which are the by-products of hydration process. Presence of free silica was found more in SC-1 and CC-1 when compared to SC-2. This indicated that further hydration was possible thereby further increase in strength can be anticipated. Hence the variation in compressive strength as discussed earlier in compressive strength test is validated from the results of SEM and EDS which explains that the presence of free silica and Ca(OH)₂ are the strength enhancing parameters.

The compressive strength of samples SC-1, SC-2 and CC-1 were compared and found that a compressive strength of 10.01 MPa was attained in the sample SC-1 in 3 days whereas a compressive strength of 10.85 MPa was attained in the sample CC-1 in 28 days which is almost equivalent and compressive strength of SC-2 was 7.65 MPa. Also from the observation, it was found that further strength gain was possible in SC-1 and concluded that steam curing cycle 1 as the desired cycle that shall be adopted for further studies.

6. CONCLUSION

In conclusion, the research findings demonstrated that the variation in compressive strength across different samples was attributed to the density variations and the extent of hydration process completion, influenced by factors such as free silica and Ca(OH)₂ presence. Optimal ratios for fly ash to cement and water content to powder ratios were determined through graph analysis, suggesting the necessity for 1.8 times the quantity of fly ash for every 1 part of cement and 0.75 times the water content to achieve the desired compressive strength of 10 N/mm².

The statistical analysis using MINITAB software revealed that significant predictors such as Cement, Fly Ash, Water, and Density for compressive strength were supported by low p-values and a high R-squared value of 97.44%. The robustness of the model was confirmed through external validation and further analysis, demonstrated its effectiveness in explaining the variability in the response variable.

Utilizing Steam Curing Cycle 1 yields potential for achieving earlier compressive strength in concrete mixes containing fly ash, as indicated by material characterization studies, validating its suitability for further investigation thereby mass production is possible which leads to faster construction practices and therefore cost is reduced.

In summary, this research aimed to develop low-cost, eco-friendly housing by replacing traditional brick masonry with Cellular Lightweight Foam Concrete (CLFC). With compressive strength of 10 MPa equivalent to that of first-class bricks, the CLFC material was utilized in constructing a model pod by adopting Mivan Technology.

7. ACKNOWLEDGMENTS

I am deeply indebted to the firm M/s Cellcon pvt. Ltd, Coimbatore and to the institutions PSG College of Technology, Coimbatore and Government College of Engineering, Salem, Tamil Nadu where all the experimental and characteristics analysis have been carried out.

8. BIBLIOGRAPHY

• ^[1]
  YASAR, E., ATIS, C.D., KILIC, A., et al, “Strength properties of lightweight concrete made with basaltic pumice and fly ash”, Materials Letters, v. 57, n. 15, pp. 2267–2270, Feb. 2003. doi: http://doi.org/10.1016/S0167-577X(03)00146-0.
  » https://doi.org/10.1016/S0167-577X(03)00146-0
• ^[2]
  HOSSAIN, K.M.A., “Properties of volcanic pumice based cement and lightweight concrete”, Cement and Concrete Research, v. 34, n. 2, pp. 283–291, Feb. 2004. doi: http://doi.org/10.1016/j.cemconres.2003.08.004.
  » https://doi.org/10.1016/j.cemconres.2003.08.004
• ^[3]
  BANTHIA, N., “A study of some factors affecting the fiber-matrix bond in steel fiber reinforced concrete”, Canadian Journal of Civil Engineering, v. 17, n. 4, pp. 610–620, 1990. doi: http://doi.org/10.1139/l90-069.
  » https://doi.org/10.1139/l90-069
• ^[4]
  PARHIZKAR, T., NAJIMI, M., POURKHORSHIDI, A.R., “Application of pumice aggregate in structural lightweight concrete”, Asian Journal of Civil Engineering, v. 13, n. 1, pp. 43–54, Feb. 2012.
• ^[5]
  SAGAR DHENGARE, W., AJAY DANDGE, L., NIKHADE, H.R., “Cellular Lightweight Concrete”, Journal of Advance Research in Mechanical and Civil Engineering, v. 2, n. 4, pp. 22–25, Apr. 2015. doi: http://doi.org/10.53555/nnmce.v2i4.332.
  » https://doi.org/10.53555/nnmce.v2i4.332
• ^[6]
  JITCHAIYAPHUM, K., SINSIRI, T., CHINDAPRASIRT, P., “Cellular lightweight concrete containing pozzolan materials”, Procedia Engineering, v. 14, pp. 1157–1164, 2011. doi: http://doi.org/10.1016/j.proeng.2011.07.145.
  » https://doi.org/10.1016/j.proeng.2011.07.145
• ^[7]
  ABDOLLAHNEJAD, Z., PACHECO-TORGAL, F., FÉLIX, T., et al, “Mix design, properties and cost analysis of fly ash-based geopolymer foam”, Construction & Building Materials, v. 80, pp. 18–30, Jan. 2015. doi: http://doi.org/10.1016/j.conbuildmat.2015.01.063.
  » https://doi.org/10.1016/j.conbuildmat.2015.01.063
• ^[8]
  DEEPA, G., MYTHILI, K., VENKATA, R., “Cellular Light Weight Concrete Blocks with different mix proportions”, International Journal of Research and Innovation, v. 2, n. 2, pp. 322–326, 2015.
• ^[9]
  GUPTA, A., RATHORE, M., “Comparative study and performance of cellular light weight concrete”, In: Proceedings of International Interdisciplinary Conference on Engineering Science and Management, Goa, India, 2016.
• ^[10]
  CHANDEL, R.V.S., SAKALE, R., “Study of Cellular Light Weight Concrete”, International Journal for Scientific Research & Development, v. 4, n.7, pp. 1–6, Oct. 2016.
• ^[11]
  GOPALAKRISHNAN, R., SOUNTHARARAJAN, V.M., MOHAN, A., et al, “The strength and durability of fly ash and quarry dust light weight foam concrete”, Materials Today: Proceedings, n. Nov, 2019. doi: http://doi.org/10.1016/j.matpr.2019.11.317.
  » https://doi.org/10.1016/j.matpr.2019.11.317
• ^[12]
  HUANG, Z., PADMAJA, K., LI, S., et al, “Mechanical properties and microstructure of ultra-lightweight cement composites with fly ash cenospheres after exposure to high temperatures”, Construction & Building Materials, v. 164, pp. 760–774, 2018. doi: http://doi.org/10.1016/j.conbuildmat.2018.01.009.
  » https://doi.org/10.1016/j.conbuildmat.2018.01.009
• ^[13]
  FU, Y., WANG, X., WANG, L., et al, “Foam concrete: a state-of-the-art and state-of-the-practice review”, Advances in Materials Science and Engineering, v. 2020, n. 1, pp. 6153602, 2020. doi: http://doi.org/10.1155/2020/6153602.
  » https://doi.org/10.1155/2020/6153602
• ^[14]
  CHICA, L., ALZATE, A., “Cellular concrete review: new trends for application in construction”, Construction & Building Materials, v. 200, pp. 637–647, 2019. doi: http://doi.org/10.1016/j.conbuildmat.2018.12.136.
  » https://doi.org/10.1016/j.conbuildmat.2018.12.136
• ^[15]
  KAMRUL HASSAN, M.D., “Experimental study on prefabricated lightweight composite wall panels under flexural loading”, Journal of Civil Engineering and Construction, v. 9, n. 4, pp. 215–225, Nov. 2020. doi: http://doi.org/10.32732/jcec.2020.9.4.215.
  » https://doi.org/10.32732/jcec.2020.9.4.215
• ^[16]
  ASHRAFIAN, A., SHOKRI, F., AMIRI, M.J.T., et al, “Compressive strength of Foamed Cellular Lightweight Concrete simulation: new development of hybrid artificial intelligence model”, Construction & Building Materials, v. 230, pp. 117048, 2020. doi: http://doi.org/10.1016/j.conbuildmat.2019.117048.
  » https://doi.org/10.1016/j.conbuildmat.2019.117048
• ^[17]
  MOHAMMADI, P.K.M., KHALILPOUR, S.H., PARSA, H., et al, “Computational performance evaluation of sacrificial protective walls composed of lightweight concrete blocks: a parametric study of blast loads in a tunnel”, Mechanics of Advanced Materials and Structures, v. 31, n. 4, pp. 880–894, 2024. doi: http://doi.org/10.1080/15376494.2022.2125134.
  » https://doi.org/10.1080/15376494.2022.2125134
• ^[18]
  BHATT, V., BHATIA, N.K., ”Study on characteristic strength of cellular light weight concrete for different proportion of composite material”, International Journal of Creative Research Thoughts, v. 11, n. 4, pp. d100-d103 Apr. 2023.
• ^[19]
  SUBRAMANI, K., GANESAN, A.K., “Synergistic effect of graphene oxide and coloidalnano-silica on the microstructure and strength properties of fly ash blended cement composites”, Revista Materia, v. 29, n. 1, pp. e20230305, 2023. doi: https://doi.org/10.1590/1517-7076-RMAT-2023-0305.
  » https://doi.org/10.1590/1517-7076-RMAT-2023-0305
• ^[20]
  AMERICAN SOCIETY FOR TESTING AND MATERIALS, ASTM C869 – Standard Specification for Foaming Agents used in making Preformed Foam for Cellular Concrete, West Conshohocken, ASTM, 2016.
• ^[21]
  AMERICAN SOCIETY FOR TESTING AND MATERIALS, ASTM C796 – Standard Test Method for Foaming Agents for use in producing Cellular Concrete using Preformed Foam, West Conshohocken, ASTM, 2016.
• ^[22]
  AMERICAN SOCIETY FOR TESTING AND MATERIALS, ASTM C495 – Standard Test Method for Compressive Strength of Lightweight Insulating Concrete, West Conshohocken, ASTM, 2016.
• ^[23]
  EUROPEAN FEDERATION DEDICATED TO SPECIALIST CONSTRUCTION CHEMICALS AND CONCRETE SYSTEMS, EFNARC – Specification and guidelines for self-compacting concrete, Farnham, EFNARC, 2002.
• ^[24]
  EUROPEAN FEDERATION DEDICATED TO SPECIALIST CONSTRUCTION CHEMICALS AND CONCRETE SYSTEMS, EFNARC – The European guidelines for self-compacting concrete specification, production and use, Farnham, EFNARC, 2005.

Publication Dates

• Publication in this collection
  08 July 2024
• Date of issue
  2024

History

• Received
  18 Apr 2024
• Accepted
  20 May 2024