Performance ability study on sludge contained hollow concrete blocks

ABSTRACT

Generation of waste from the consumption of human society at the global level is an increment level day by day. The daily life requirements of the human society start from water consumption, clothes, vehicles for travel, power consumption, drugs etc. The utilization of these facilities by the public leads to different pollution and also generation of waste in different forms. The disposal of the generated waste poses a threat to the human society which needs more attention in the present scenario. Also, utilization of waste results in a sustainability by reducing their environmental footprints and conserving resources. In this article, the sludge generated from the textile industry effluents after its treatment and hypo sludge a waste generated from paper industry were taken for the experimental study. The physico chemical characteristics were analyzed and an attempt was made to utilize the sludge to replace cement in the manufacturing of hollow concrete blocks. The hollow concrete blocks were cast and tested as per the recommendations of BIS standards. The experimental study reveals that about 10% of cement can be replaced effectively for the manufacturing of hollow concrete blocks and possible standards are achieved.

Keywords:
Disposal; Reuse; Hollow concrete blocks; Waste utilization; Waste management

1. INTRODUCTION

Many industrial materials and wastes are utilized to substitute non-renewable virgin materials that must be extracted and processed for application, Industrial Materials Recycling (IMR) preserves natural resources and minimizes the energy consumption and pollution allied with these actions. For instance, substituting coal fly ash (an industrial waste material) for Portland cement in concrete reduces the energy and greenhouse gas emissions associated with the production of cement. The positive use of industrial waste materials consequences in a reduced amount of material sent to dumping facilities which save landfill space occupation and further reduces greenhouse gas emissions and other pollutants. The textile dyeing and finishing industry have contributed a huge pollution threat as it is one of the utmost chemically focused industries on earth and the No. 1 polluter of fresh, clean water (after agriculture). Decreasing the use of natural resources as construction materials, alternative construction materials are formulated by the construction sectors worldwide to safeguard the natural resources and to use the waste and industrial by-products. Hollow and dense cement concrete blocks are recognized as hollow concrete blocks. These have been established as an alternate option to bricks in case of construction of partition and non-load bearing walls which are generally used in construction works. The hollow concrete blocks comprise of raw materials such as cement, stone chips, stone dust and sand. The hollow concrete blocks are not only cheaper than bricks but have added proficiency as well. These blocks have more tensile strength, the walls constructed from these blocks performs as thermal insulators as of their hollowness.

JAAFAR et al. [¹] had conducted a primary study to accomplish price marketplace objects in the construction of walls for inexpensive structures with load-bearing hollow masonry units using the ACI 211.1 [²] blend design by a slump range of 25–50 mm that trails the specification parameters of IQS 1077. TRAN et al. [³] prepared concrete specimens with various proportions of the RCA (25%, 50%, 75%, and 100%). The outcomes disclosed insignificant differences between the recycled concrete (RC) and reference concrete in terms of the mechanical and durability-related measurements. AL-TARBI et al. [⁴] developed an eco-friendly hollow concrete blocks in the field using wasted high density polyethylene, low density polyethylene and crumb tire rubber in order to reduce CO₂ pollution in the world.

In this study, an attempt has been done to observe the characteristics of hollow concrete blocks comprising with textile sludge and hypo sludge which has substituted cement to a possible level so that production of cement can be reduced to a possible extent resulting in the reduction of emission of CO₂ in the atmosphere and also an effective solution for the disposal of textile and hypo sludge.

2. REVIEW OF LITERATURE

The implementation of cleaner production in the textile industry extends beyond creating new alternative materials to include opportunities for technical advancements as well [⁵, ⁶, ⁷, ⁸]. MEDA et al. [⁹] presented the different studies carried out to reuse the waste sludge in making different construction materials. XIA et al. [¹⁰] critically reviewed the current status of recycling sludge and sludge ash into low-carbon construction materials and highlighted the future perspectives of sludge-derived construction materials. DEEPIKA et al. [¹¹] discussed about the environmental and economic benefits of recycling and reusing industrial sludge in the construction industry, which lead to not only safe disposal of industrial waste but also reduce the burden of raw material needed for construction purposes. Waste materials generated from water and sewage treatment processes and power plants are feasible to be used as ingredients for paving concrete block production [¹²]. Using regular Portland cement, surplus sludge from sewage treatment plants was solidified to investigate the potential for application in construction materials from the standpoint of mechanical properties [¹³]. The sewage sludge was incinerated, and XRF and X-ray diffraction (XRD) tests were performed on the resulting sewage sludge ash. The ash was utilized in different proportions in the mortar and concrete specimens, and compressive strength tests were conducted on the resulting specimens. The results indicate that using 20% SSA instead of cement resulted in a 25% reduction in compressive strength in concrete specimens [¹⁴]. MAROLIYA [¹⁵] concluded that the strength of wall constructed with hollow concrete block gave the less strength when compared to the brick masonry but the cost of construction was very less. MAROLIYA [¹⁶] concluded that the strength of the column constructed with hollow concrete blocks gave the less strength when compared to the brick masonry. But the cost of the wall built with hollow concrete blocks was very much less than that of the brick masonry. SURESHCHANDRA et al. [¹⁷] studied the production of hollow concrete blocks, sand was replaced partly (i.e. 50% replacement) by quarry dust instead of complete replacement. The 50% replaced blocks were performed better than the blocks which were set conventionally by means of natural sand. Additionally, the admixtures could be added in the making of blocks for improved performance. It was concluded that the hollow concrete blocks could be used in load-bearing masonry structures. KHAN et al. [¹⁸] had carried out with M20 & M30 grade concrete with w/c ratio of 0.55 & 0.45 respectively as a control specimen and hypo sludge is replaced in different percentages such as 10%, 20%, and 30% by weight of cement Compressive strength of concrete with various mixes with different curing periods which are 3, 7, 28 days by partial replacement of cement with hypo sludge that is 0%, 10%, 20%, 30%. KULKARNI et al. [¹⁹] paper waste can be recycled only a limited number of times before they become too short or weak to make high quality paper. Thus, the broken, low quality paper fibers are separated out to become waste sludge known as hypo sludge, which can be available at very negligible rate and in huge quantity from paper Industry. Hypo sludge has a very good content of CaO, study on hypo sludge for making bricks is done by partial replacement with lime in fly ash bricks. The replacement of hypo sludge by weight with lime with permutation of 5%, 10%, 15% and 20% is done. These bricks were tested in compression test and water absorption test per Indian Standards. The aim of this research is to make economical and green bricks to maintain environmental balance, and avoid problem of ash disposal. BALAMURUGAN and KARTHICKRAJA [²⁰] had concerned with experimental investigation on strength of concrete and optimum percentage of the partial replacement by replacing cement via 5%, 10%, 15%, and 20% of Hypo Sludge. The aim of investigation is behavior of concrete while adding of waste with different proportions of Hypo sludge in concrete by using tests like compression strength and split strength. The mix design was carried out for M25 grade concrete as per IS: 10262–2009 [²¹]. BALASUBRAMANIAN et al. [²²] concluded that the blocks with 20% sludge as cement replacement met the BIS specification for the load bearing units, and the blocks with 30% sludge as cement replacement met the BIS specification for non-load bearing units. Water absorption of all blocks is less than the 10% prescribed by IS 2185 (part I) – 1979 [²³]. PITRODA et al. [²⁴] had attempted to study the properties of Paper Industry Waste (Hypo Sludge) concrete to check its durability. The mix design was carried out for M25 and M40 grade concrete as per IS: 10262–2009 [²¹]. The water absorption of M25 Paper Industry Waste (Hypo Sludge) concrete is higher than water absorption of M40 grade concrete. SOLANKI et al. [²⁵] had investigated on strength of the concrete and optimum percentage of the partial replacement by preparing a mix M20 grade. The design mix proportion used were Conventional Concrete, 10%, 20%, 30%, 40% replacement of cement by industrial waste like fly ash and hypo sludge. In the test performed, the optimum compressive stress obtained by utilizing paper waste at 30% replacement. At the place where strength is not more importance or rather structure is for temporary basis then design mix proportion up to 40% replacement can also be utilized. PATEL et al. [²⁶] used hypo sludge was as a replacement to cement. Replacement percentages used during the present study were 10%, 15%, 20%, 25%. Compressive strength of cubes was found on 3days, 7days, and 28days. The 28thday flexural strength and split tensile strength of the specimens was found on the respectively beams and cylinders. ZALA et al. [²⁷] replaced hypo sludge within the range of 10–40% by weight of cement. In the present study, 5 different mixes of Hypo Sludge are tested for parameters like: compressive strength, flexural strength and cost. Thus, textile wastewater treatment plant chemical sludge could be reused in a variety of construction applications [²⁸, ²⁹, ³⁰].

3. MATERIALS AND METHODS

3.1. Materials and proportioning of materials

The materials used in the production of hollow concrete blocks are cement, stone dust and coarse aggregate or stone chips collected from crusher passing through 10 mm sieve and retained on 4.75 mm sieve, textile sludge, hypo sludge and required quantity of water.

• Portland Pozzolona cement confirming to IS 1489:1991 was used for the entire experimental works. The specific gravity of the cement used is 2.92 and having a block density of 1400 kg/m³ [³¹].

• The stone dust was selected from the nearest source as a raw material without any processing of the dust from the quarry. The specific gravity and pH of quarry dust used are found to be 2.7 and 8.84.

• Machine crushed granite metal of maximum size 20 mm confirming to IS 383–1970 with a bulk density of 1700 kg/m³ was used in the present investigation. The specific gravity of the coarse aggregate sample was found to be 2.7. Fineness modulus of coarse aggregate was found to 7.16.

3.2. Energy dispersive analysis of x-rays (EDAX)

The chemical composition of the textile sludge has been evaluated using EDAX software. The Table 1 and Figure 1 illustrates the chemical oxides exists and the percentage of components found in the textile sludge. It is observed that the sample has the chief component of calcium oxide (CaO) which amounts to 53.06%, and the iron oxide is the second main component and amounts to 23.23%. The Al₂O₃ component is 0.68%. From this outcome, the amount of CaO + Al₂O₃ + Fe₂O₃ is equal to 76.97%. According to ASTM standard for a pozzolanic material, these oxide percentages should be more than 70%. The composition of CaO is more than 20% and amounts to 53.06%.

Table 1
Chemical composition of CETP textile sludge from energy dispersive analysis of X-ray (EDAX).

CHEMICAL COMPOSITION OF TEXTILE SLUDGE
SL. NO	OXIDES PRESENT	PERCENTAGE COMPOSITION (%)
1	Magnesium Oxide (MgO)	1.01
2	Silicon-di-oxide (SiO2)	0.91
3	Calcium oxide (CaO)	53.06
4	Iron oxide (FeO)	23.23
5	Copper oxide (CuO)	2.16
6	Aluminium oxide (Al2O3)	0.68
7	Phosphorous pentoxide (P2O5)	0.32
8	Sulphur tri-oxide (SO3)	0.92
9	Potassium oxide (K2O)	0.17

Figure 1
Textile sludge view through EDAX Software at spectrum 5 & 8.

3.3. Field emission scanning electron microscopy (FESEM)

The field emission microscopic pictures of the textile sludge samples are shown in Figure 2 through different intensifications. From the microscopic structure, it is understood that a spongy structure with consistent mass ensues. The existence of cellulose materials fetches the cohesive nature of the material.

Figure 2
FESEM view of textile sludge with high and low magnification.

The hypo sludge collected from the open yard was characterized by its several physic-chemical parameters like total solids, total volatile solids, heavy metals, etc. Table 2 expresses the physicochemical properties of the sludge collected.

Table 2
Physico-chemical properties of hypo sludge.

PARAMETER	VALUE
pH value	12.20
Specific gravity	2.23
Density	846 Kg/m3
Total solids	57.46%
Total volatile solids	2.67%
Total fixed solids	54.79%
Electrical conductivity	10350 µs/cm
Magnesium	309 mg/l
Copper	8.05 mg/kg
Zinc	47.03 mg/kg
Nickel	44.6 mg/kg
Lead	*Bdl
Chromium	25.07 mg/kg
Cadmium	*Bdl
Lime (CaO)	68.08%
Silica(SiO2)	2.25%
Alumina (Al2O3)	1.17%
Magnesium (MgO)	0.73%

• *Bdl- Below deduction limit

The hypo sludge was observed to be white in color and odorless in nature. The pH value was found to be 12.20 and highly alkaline in nature. The specific gravity and density of the trial collected reveals that there is an option to frame lightweight composite materials using the sludge. The value of electrical conductivity for the sample was 10350 µs/cm. This value replicates the occurrence of concentrations of ionic compounds in the sludge. The total solids in dry state were found to be 57.46% and volatile solids to be 2.67%. This specifies that the sludge comprises 2.67% of organic matters and the respite is considered as fixed solids which comprise inorganic solids. The sludge sample too comprises heavy metals like copper, zinc, nickel, lead, chromium, etc. which are very usually found in the textile effluents owed to the usage of dyes and various chemicals. It is observed that the trial has the major component of calcium oxide (CaO) which amounts to 68.08%. From the chemical analysis, it is recognized that the hypo sludge samples have gained probable cementing property.

The field emission microscopic pictures of the hypo sludge samples are shown in Figure 3 with different magnifications. The coarse structure is recognized with the presence of homogeneous mass.

Figure 3
FESEM view of hypo sludge with high and low magnification.

As per the recommendations of IS: 2185–2005 [²³], the concrete mix proportioned for blocks will be one part by volume of cement to 6 parts by volume of combined aggregates before mixing (1:6). In this study, 1 part of cement, three parts of stone dust and three parts of stone chips were proportioned by weight. The mix proportion was designated as 1:3:3.

3.4. Manufacturing of hollow concrete blocks

The hydraulically functioned hollow concrete block production machine with 10.5HP motor with electrical panel and mould of size 400 × 100 × 200 mm as shown in Figure 4, having ten blocks /stroke was used for the manufacture of blocks. The mix combinations as per the recommendation of BIS is articulated and presented in Table 3. The mix proportions with planned combinations were mixed methodically in the concrete mixer affording to the procedure and the batches of the mix were fed into the machine platforms using trolley and shovel. The mix was then spread into the mould for vibration and shaped to appear. The blocks were shaped in egg laying mode with the machine and kept caringly since it was in wet and wabbly condition and even it may be disrupted with a slight disturbance. The undisturbed blocks were held for water spray curing in open air for 28 days.

Figure 4
Dimensions of hollow concrete block.

Table 3
Mix combinations for the production of hollow concrete blocks.

SL.NO.	MIX COMBINATIONS	TOTAL % OF REPLACEMENT	% OF TEXTILE SLUDGE	% OF HYPO SLUDGE
1	CS	0	0	0
2	TS05	5	5	0
3	TS10	10	10	0
4	TS15	15	15	0
5	TS20	20	20	0
6	TS25	25	25	0
7	TS30	30	30	0
8	HS05	5	0	5
9	HS10	10	0	10
10	HS15	15	0	15
11	HS20	20	0	20
12	HS25	25	0	25
13	HS30	30	0	30
14	THS05	5	2.5	2.5
15	THS10	10	5	5
16	THS15	15	7.5	7.5
17	THS20	20	10	10
18	THS25	25	12.5	12.5
19	THS30	30	15	15

3.5. Experimental Procedure

The hollow concrete block manufacturing machine can give an output of ten blocks/stroke. As per the recommendations of IS:2185–2005 [²³], it is requisite to calculate the mean compressive strength for eight hollow concrete blocks and three blocks for computing water absorption and block density for the stated 19 combinations in Table 3. A total number of 190 blocks were cast and set aside for curing as shown in Figure 5.

Figure 5
Casting and curing of hollow concrete block specimens.

The Standard tests for the cast specimens, recommendations, testing methodology, sample selection and inferences are referred, compared and presented in the results and discussions chapter based on the specifications recommended in IS: 2185–2005 Part 1, 2, 3 and 4 of the Bureau of Indian Standards [²³].

4. RESULTS AND DETAILED DISCUSSIONS

The parameters discussed are the compressive strength, block density and water absorption based on the recommendations of IS: 2185–2005 and shown in Table 4 and Figures 6, 7 and 8 respectively.

Table 4
Results attained from hollow concrete block specimens.

SL.NO	MIX COMBINATIONS	COMPRESSIVE STRENGTH (N/mm2)	BLOCK DENSITY (kg/m3)	WATER ABSORPTION (%)
1	CS	3.37	1865.00	4.67
2	TS05	3.51	1788.50	4.79
3	TS10	3.36	1796.00	5.05
4	TS15	2.97	1801.50	5.39
5	TS20	2.88	1765.00	5.49
6	TS25	2.74	1731.25	5.87
7	TS30	2.54	1710.00	5.94
8	HS05	3.53	1872.50	5.39
9	HS10	3.38	1842.50	5.4
10	HS15	3.22	1841.25	5.43
11	HS20	3.08	1830.00	5.45
12	HS25	2.93	1823.75	5.59
13	HS30	2.76	1797.50	5.97
14	THS05	3.55	1806.88	5.12
15	THS10	3.34	1815.00	5.22
16	THS15	3.12	1816.88	5.38
17	THS20	3.02	1797.50	5.48
18	THS25	2.82	1777.50	5.72
19	THS30	2.62	1760.00	5.93
Mean		3.09	1802.03	5.44
Standard Deviation		0.32	41.67	0.36
Coefficient of Variation		0.10	0.02	0.07

Figure 6
Compressive strength of hollow concrete block specimens.

Figure 7
Block density of hollow concrete block specimens.

Figure 8
Water absorption of hollow concrete block specimens.

The parameters deliberated are the compressive strength, block density and water absorption based on the recommendations of IS: 2185–2005. The block densities of all the mix combinations for the average of 3 specimens observed are not less than 1500 kg/m³ and may be denoted as Grade A blocks conferring to the recommendations of IS: 2185–2005. The combinations TS05, 10 and 15, HS05, HS10, HS15 and HS20, THS05, THS10 and THS15 have recorded block densities more than 1800 kg/m³. Moreover, they were also to be compared with the corresponding compressive strengths. The water absorption of all the combinations for the average of 3 specimens was observed. The maximum water absorption recorded for the combinations is not more than 6% satisfying the eligibility criteria of not more than 10% recommended by IS: 2185–2005. None of the combinations has recorded water absorption more than 6%. This shows that the sludge added concrete block specimens hold good performance concerning water absorption for all the mix combinations proportioned.

The compressive strength of the hollow concrete sample blocks declines when the percentage of sludge increases. The damage mode of the blocks occurred due to crush and cracks at the corners of the hollows. Meanwhile, failure had also occurred due to the combination of crushing and tensile stresses due to localized crushing and cracking. The combinations TS05, HS05 and THS05 have achieved the compressive strength more than 3.5 N/mm² from the mean of 8 specimens and satisfied the Grade A block as recommended by IS: 2185–2005. The block specimens TS05, TS10, HS10, HS15, HS20, THS10, THS15 and THS20 have also achieved more than 3 N/mm². The drop in strength may be due to the cohesive action and coarse structure of textile sludge and the chlorides present in it. It was also observed that further substitution of cement with sludge other than the above stated combinations results in further decline of compressive strength less than 3 N/mm². Moreover, the standard deviation and coefficient of variation arrived for the mean value of the samples are reasonable.

• According to the outcomes from the Energy dispersive analysis of x-rays (EDAX), oxide percentages (CaO + Al₂O₃ + Fe₂O₃ = 7 6.97%) whereas the ASTM standard for a pozzolanic material for these oxide percentages should be more than 70% which is well satisfied.

• The Field emission scanning electron microscopy (FESEM) of textile sludge and hypo sludge confirms about the cohesive nature and coarse structure of the sludge and composition of textile sludge and hypo sludge reveals that the presence of calcium oxide (CaO) which results in utilization of these sludges in the production of construction blocks.

• Results from the tests like compressive strength (average of eight specimens), block density (average of three specimens) and water absorption (average of 3 specimens) as per the recommendations of IS: 2185–2005 were observed and satisfied for the combinations TS05, HS05 and THS05 which had achieved the compressive strength more than 3.5 N/mm² from the mean of 8 specimens and satisfied the Grade A block as recommended by IS: 2185–2005 [²³].

5. CONCLUSIONS AND RECOMENDATIONS

From the outcomes of the experimental investigations, it was concluded that:

• The hollow concrete blocks of the mix combinations TS05, HS05 and THS05 had achieved the requirements with respect to compressive strength, block density and water absorption satisfies as Grade A blocks as per the recommendations of the Bureau of Indian Standards and can be used as exterior and interior wall construction.

• It was observed that the mix combinations TS10, HS10 and THS10 had achieved the requirements with respect to block density and water absorption and more than 95% of the required compressive strength as Grade A blocks as per the recommendations of the Bureau of Indian Standards and can be considered to be used for only interior wall construction.

• Therefore, the textile sludge and hypo sludge can be replaced up to a maximum of 10% for cement in the casting of hollow concrete blocks which leads for the possible use of the waste sludge generated and as well as an effective solution for the sludge disposal.

• However as per the arrived standard deviation and coefficient of variation obtained shows that almost the replaced designated samples can be utilized for the construction of interior or exterior walls.

• It is highly recommended that the replacement of cement to sludge given in the combinations can be replaced up to 5% and strongly utilized for the construction of interior and exterior wall construction.

• It is highly recommended to extend the research in future for the replacement of sludge up to 10% for cement with or without admixtures so as to utilize the same in construction of interior and exterior walls.

6. BIBLIOGRAPHY

• ^[1] JAAFAR, A.S., ABBAS, Z.K., ALLAWI, A.A., “Investigating the ability of producing sustainable blocks using recycled waste”, Engineering, Technology & Applied Scientific Research, v. 13, n. 6, pp. 12006–12011, 2023. doi: http://doi.org/10.48084/etasr.6357.
  » https://doi.org/10.48084/etasr.6357
• ^[2] AMERICAN CONCRETE INSTITUTE, ACI 211.1 Standard Practice for Selecting Proportions for Normal, Heavy weight, and Mass Concrete, Michigan, EUA, 1991.
• ^[3] TRAN, D.V.P., ALLAWI, A., ALBAYATI, A., et al., “Recycled concrete aggregate for medium-quality structural concrete”, Materials, v. 14, n. 16, pp. 4612, 2021. doi: http://doi.org/10.3390/ma14164612. PubMed PMID: 34443133.
  » https://doi.org/10.3390/ma14164612
• ^[4] AL-TARBI, S.M., AL-AMOUDI, O.S.B., AL-OSTA, M.A., et al., “Development of eco-friendly hollow concrete blocks in the field using wasted high-density polyethylene, low-density polyethylene, and crumb tire rubber”, Journal of Materials Research and Technology, v. 21, pp. 1915–1932, 2022. doi: http://doi.org/10.1016/j.jmrt.2022.10.027.
  » https://doi.org/10.1016/j.jmrt.2022.10.027
• ^[5] GAVRILESCU, M., “Cleaner production as a tool for sustainable development”, Environmental Engineering and Management Journal, v. 3, n. 1, pp. 45–70, 2004. doi: http://doi.org/10.30638/eemj.2004.006.
  » https://doi.org/10.30638/eemj.2004.006
• ^[6] GAVRILESCU, M., ASACHI, G., “Cleaner production as a tool for sustainable development”, Environmental Engineering and Management Journal, v. 3, n. 1, 2017.
• ^[7] SCHRAMM, W., “Possibilities and limitations of a comparative assessment of process technologies from a cleaner production point of view”, Journal of Cleaner Production, v. 6, n. 3–4, pp. 227–235, 1998. doi: http://doi.org/10.1016/S0959-6526(98)00017-1.
  » https://doi.org/10.1016/S0959-6526(98)00017-1
• ^[8] TONG, O., SHAO, S., ZHANG, Y., et al., “An AHP-based water-conservation and waste-reduction indicator system for cleaner production of textile-printing industry in China and technique integration”, Clean Technologies and Environmental Policy, v. 14, n. 5, pp. 857–868, 2012. doi: http://doi.org/10.1007/s10098-012-0453-x.
  » https://doi.org/10.1007/s10098-012-0453-x
• ^[9] MEDA, S.R., SHARMA, S.K., TYAGI, G.D., “Utilization of waste sludge as a construction material-a review”, Materials Today: Proceedings, v. 46, n. 9, pp. 4195–4202, 2021.
• ^[10] XIA, Y., LIU, Y., WANG, L., et al., “Value-added recycling of sludge and sludge ash into low-carbon construction materials: current status and perspectives”, Low-Carbon Materials and Green Construction, v. 1, n. 1, pp. 23, 2023. doi: http://doi.org/10.1007/s44242-023-00023-5.
  » https://doi.org/10.1007/s44242-023-00023-5
• ^[11] DEEPIKA, SAMRITI, SHARMA, G., KAUR, H., KUMAR, S., & CHADHA, P., “Sustainable utilization of industrial sludge in the construction industry”, In: Kumar, V., Bhat, S.A., Verma, P., Kumar, S. (eds), Recent trends in management and utilization of industrial sludge, Cham, Springer, pp. 209–253, 2024.
• ^[12] CHENG, W.N., YI, H., YU, C.F., et al., “Biorefining waste sludge from water and sewage treatment plants into eco-construction material”, Frontiers in Energy Research, v. 7, pp. 22, 2019. doi: http://doi.org/10.3389/fenrg.2019.00022.
  » https://doi.org/10.3389/fenrg.2019.00022
• ^[13] LIANG, J., HE, H., WEI, J., et al., “Study of solidifying surplus sludge as building material using ordinary portland cement”, Processes, v. 10, n. 11, pp. 2234, 2022. doi: http://doi.org/10.3390/pr10112234.
  » https://doi.org/10.3390/pr10112234
• ^[14] AZARHOMAYUN, F., HAJI, M., KIOUMARSI, M., et al., “Combined use of sewage sludge ash and silica fume in concrete”, International Journal of Concrete Structures and Materials, v. 17, n. 1, pp. 34, 2023. doi: http://doi.org/10.1186/s40069-023-00593-5.
  » https://doi.org/10.1186/s40069-023-00593-5
• ^[15] MAROLIYA, M.K., “Load carrying capacity of hollow concrete block masonry wall”, International Journal of Engineering Research and Applications, v. 2, n. 6, pp. 382-385, 2012.
• ^[16] MAROLIYA, M.K., “Load carrying capacity of hollow concrete block masonry column”, Journal of Engineering, v. 2, n. 10, pp. 5-8, 2012.
• ^[17] SURESHCHANDRA, H.S., SARANGAPANI, G., KUMAR, B.N., “Experimental investigation on the effect of replacement of sand by quarry dust in hollow concrete block for different mix proportions”, International Journal of Environmental Sciences and Development, v. 5, n. 1, pp. 15, 2014.
• ^[18] ABDULLAH SHAHBAZ KHAN., RAM PANTH., GAGAN KRISHNA R R., SURESH G PATIL., “Structural Performance of Concrete by Partial Replacement of Cement with Hypo Sludge (paper waste)”, International Journal of Emerging Technologies and Engineering, v.1, n.7, pp. 175–181, 2014.
• ^[19] APURVA KULKARNI., SAMRUDDHA RAJE., JUNED PEERZADA., MAMATA RAJGOR., “A Miniscule Endeavour for Accomplishing Hypo Sludge Fly Ash Brick in Indian Context”, International Journal of Engineering Trends and Technology , v.10, n.7, pp. 361–365, 2014.
• ^[20] BALAMURUGAN, R., KARTHICKRAJA, R., “An experimental investigation of partial replacement of cement by industrial waste (Hypo Sludge)”, International Journal of Engineering Research and Applications, v. 4, n. 1, pp. 430–435, 2014.
• ^[21] BUREAU OF INDIAN STANDARDS, IS: 10262–2009 Guidelines for Concrete Mix Design Proportioning, New Delhi, 2009.
• ^[22] BALASUBRAMANIAN, J., SABUMON, P.C., LAZAR, J.U., et al., “Reuse of textile effluent treatment plant sludge in building materials”, Waste Management, v. 26, n. 1, pp. 22–28, 2006. doi: http://doi.org/10.1016/j.wasman.2005.01.011. PubMed PMID: 16287597.
  » https://doi.org/10.1016/j.wasman.2005.01.011
• ^[23] BUREAU OF INDIAN STANDARDS, IS 2185 (Part I), Concrete Masonry Units, New Delhi, 2005.
• ^[24] PITRODA, J., ZALA, L.B., UMRIGAR, F.S., “Durability of concrete with partial replacement of cement by paper industry waste (Hypo Sludge)”, International Journal of Innovative Technology and Exploring Engineering, v. 2, n. 3, pp. 101–104, 2013.
• ^[25] SOLANKI, J.V., PITRODA, J., “Investigation of low-cost concrete using industrial waste as supplementary cementitious materials”, International Journal of Engineering Science and Innovative Technology, v. 2, n. 1, 2013.
• ^[26] PATEL, R.A., JAMMU, M.A., “Experimental study of concrete made with hypo sludge”, Journal of International Academic Research for Multidisciplinary, v. 2, n. 2, 2014.
• ^[27] JAYESH KUMAR PITRODA., LAXMANSINGH B. ZALA., UMRIGAR F S., “A Techno-Economic study on paper industry waste hypo sludge concrete in rigid pavement”, International Journal of Civil, Structural, Environmental and Infrastructure Engineering Research and Development, v.3, n.5, 2013.
• ^[28] PATEL, H., PANDEY, S., “Exploring the reuse potential of chemical sludge from textile wastewater treatment plants in India-A hazardous waste”, American Journal of Environmental Sciences, v. 5, n. 1, pp. 106, 2009.
• ^[29] VELUMANI, P., SENTHIL KUMAR, S., PREMALATHA, P.V., “An innovative approach to evaluate the performance of sludge-incorporated fly ash bricks”, Journal of Testing and Evaluation, v. 44, n. 6, pp. 2155–2163, 2016. doi: http://doi.org/10.1520/JTE20140508.
  » https://doi.org/10.1520/JTE20140508
• ^[30] VELUMANI P., SENTHIL KUMAR S., “Production of sludge-incorporated paver blocks for efficient waste management”, Journal of the Air & Waste Management Association, v.68, n.6, pp. 626–636, 2018. doi: https://doi.org/10.1080/10962247.2017.1395373.
  » https://doi.org/10.1080/10962247.2017.1395373
• ^[31] BUREAU OF INDIAN STANDARDS, IS 1489:1991 Portland Pozzolana Cement (PPC), New Delhi, 1991.

Publication Dates

• Publication in this collection
  25 July 2025
• Date of issue
  2025

History

• Received
  04 Mar 2025
• Accepted
  03 June 2025