Ecofriendly Paver Block

In the past few decades, the rapid process of industrialization and urbanization has increased the generation of waste material at huge rates and landfills are filling up faster than the exploration of new sites. Disposal of industrial waste is one of the serious problems faced worldwide. There is now a significant interest to solve the environmental problem caused by industrial waste and other similar materials by adding such material in manufacture of concrete. The use of paver block technique has been introduced in construction a decade ago, for specific purpose namely footpath, parking area etc. but now being adopted extensively for different units where the conventional concrete of pavement using bituminous mix or cement concrete technique is not feasible or desirable. This study looked at the feasibility of dry textile sludge and steel slag inclusion as partial cement and coarse aggregates replacement system. Properties of concrete replacing dry textile sludge as partial substitution around of 2.5% and 5.0% were investigated. Also the concrete replacing steel slag as partial substitution for CA amounts of 10, 20, 30, and 40% were investigated. The waste material was obtained from steel and textile industry. The results obtained clearly show that steel slag and textile sludge enhance the comparative strength properties of the final concrete product. The research indicates that waste steel slag can effectively be used as CA replace (up to 20%) and also waste dry text tile sludge can effectively be used as cement replacement (up to 2.5%) for substantial change in strength.
Dr. S. P. Ahirrao, Ph.D., Associate Professor Civil Department SIEM Nasik.

Introduction
Disposal of waste is one of the serious problems faced by our country. This may be steel industry textile, plastic industry, etc. Disposal of such waste may cause harmful effect on health of human being. The sludge disposal like composting, open dumping, land filling has some drawback like decreasing in productivity of land, contamination of underground water requires large area for storage and high cost of disposal

Textiles sector is one of the most polluting sectors in India. There are 240 dyeing industries which produces about 80 million tons of textile sludge as a byproduct [5]. Due to its chemical and minerals contents, these wastes are found to be hazardous in the view of environmental consideration. Unsafe disposal of such waste may cause harmful effect on the environment and human being. Textile sludge is the combination of waste water from various stages of production: Fibers preparation, thread, webbing, dyeing and finishing. The textile sludge has a high calcium and magnesium content.

At the same time the problem of steel slag utilization is not confined to India alone but is being experienced all over the world. Steel slag is a byproduct generated during the steel manufacturing process [6]. Disposal of such waste is very important as it may cause harmful effect to human being. Solid waste management should be given more importance for the safe disposal of such waste. Concrete plays an important role in the infrastructure development. Almost 70% of the volume of the concept is composed of aggregates. To meet the world wide demands of concrete in the future, it is becoming a challenging task to find suitable alternate to natural aggregate for making concrete. Availability of aggregates is getting depleted and also it becomes costly, therefore the partial replacement of natural aggregates by the industrials waste has been continuously emphasized during recent year [1].

Concrete paving block has been extensively used in many countries as a specialized problems solving technique for providing pavement in areas where conventional types of construction are less durable due to many operational and environmental constraint. This technology has been introduced in India in construction a decade ago, for specific requirement namely footpaths, parking areas etc. But now being adopted extensively where the conventional construction of pavement using, bituminous mix or cement concrete technique are not feasible or desirable. Concrete power blocks were first introduced in Holland in fifties [2].

Paver blocks are rectangular in shape and had more or less the same size as the bricks. During the past five decades the block shape has steadily evolved from non-interlocking to partially interlocking to fully interlocking to multiple interlocking shapes. In recent years there has been an increasing worldwide demand of concrete paving blocks for the footpath, roads and airfields which has led to a local depletion of aggregates.

Raghuntahan et al. (2010) have conducted a study on strength of concrete with influent treatment plant sludge from dyeing industries which will not be affecting the strength of concrete [4]. Praveen et al.; (2013) have conducted a study on steel slag as an ingredient of concrete [3]. Partial replacement of CA with steel slag gives adequate result of strength. Many researchers used these waste as partial replacement as concrete ingredient separately.

So there is scope to use steel slag as CA and dry textile sludge as partial replacement of cement in the production of paver blocks. Thus replacing partially the natural aggregate in concrete with steel slag and cement with dry textile sludge would lead to considerable environmental benefit and would be economical.

Experimental Work
The main objective of the experimental program was to obtain the best replacement level of the both steel slag and textile slag in coarse aggregates and cement without affecting the strength properties like c/s and abrasion resistance of paver block. The experimental work was carried out on M30 grade concrete. Paver block to find the effect of steel slag and textile sludge on the various mechanical properties. The concrete mix was designed following the guideline given in IS 10262:2009. Ordinary Portland cement 53 having Sp. gravity 3.15 was used. River sand having a Sp. gravity 2.71 and FM of 3.20 was used as FA. The CA was 20mm and down well graded black basalt rock having Sp.GR of 2.83. The addition of steel slag to concrete was for replacing CA where as that of textile sludge was for replacing cement. M.30 concrete had cement sand and CA in the ratio 1:2.11:2.69 respectively. The water to cement ratio was 0.45. The assumed quality control was good with 5% result falling below the prescribed limit in the code. According to IS 10262 the standard deviation for very good and good quality control is 3.6 and 4.6. However according to IS 456:2000. The assumed standard deviation for M30 mix design for controlled quality for addition of water regular checking of material aggregates grading and moisture contained and periodical checking of workability and strength of concrete mix in mechanical mixer is 5.0. The experimental work includes testing mechanical prosperities such as compressive strength and abrasion resistance. Concrete paver blocks were cast and tested for compressive strength and abrasion resistance.

Almost all specimens were water cured for up to 28 days before testing. The workability was measured by slump test. Table 1 gives the details of various mixes prepared by replacing either CA or cement. The water to cement ratio in all the cases was maintained at 0.45.

Table -1:- Details of concrete prepared by replacing aggregate by steel slag and cement by dry textile sludge
Sr. No.	Designation	Details of Replacement Made	Ratio of C:TS:S:SS:CA
1	TS 0	Conventional M30 concrete	1:0:2.11:0:2.69
2	TS1	2.5% Cement replacement by textile sludge	1:0.026:2.16:0:2.75
3	TS 2	5% Cement replacement by textile sludge	1:0.055:2.22:0:2.83
4	SS 1	10% CA replacement by steel slag	1:0:2.11:0.25:2.42
5	SS 2	20% CA replacement by steel slag	1:0:2.11:0.54:2.15
6	SS 3	30% CA replacement by steel slag	1:0:2.11:0.81:1.88
7	SS 4	40% CA replacement by steel slag	1:0:2.11:1.07:1.62
8	TSSS-1	2.5% Cement replaced by TS & 20% CA by SS	1:0.026:2.16:0.55:2.20
9	TSSS-2	5% Cement replaced by TS & 20% CA by SS	1:0.053:2.22:0.057:2.26
C=Cement, TS= Textile Slag, S=Sand, SS=Steel slag, CA= Coarse Aggregate

Result and Discursion
Table 2 compare the water absorption compressive strength and abrasion resistance of paver blocks containing steel slag and textile slag with those of the plain cement concrete paver block. The compressive strength comparison shows that in some cases the paver block meets the design strength despite, the addition of waste steel slag and textile sludge. The variation in water absorption and abrasion resistance is typical for an experiment of this kind. These two specimen namely The specimen with 20% steel slag (SS2) and the specimen with 2.5% textile slag 20% steel slag (TSSS1) show the best strength among the specimen containing Industrial waste. The reason for achieving the peak best strength abrasion resistance could be in the filling of wades in CA by steel slag and FA by textile sludge.


The water absorption gradually increases as the % of replacement of steel slag. Increasing water absorption may be due to the cement mortar adhered to the surface of aggregate which absorb more water. As per IS 15658:2006 the water absorption is within permissible limit hence steel slag inclusion does not cause excessive water absorption. The absorption resistance is required to resist the wearing surface of paver block. More is the abrasion wear poor is the concrete paver block. As steel slag has higher Sp. gravity and lower impact value i.e. strong exceptionally tough the abrasion resistance is more & abrasive wear is low.


Conclusion
Incorporating 2.5% waste textile in place of cement & 20% waste steel slag in place of aggregate in concrete of paver block give acceptable mechanical properties such as compressive strength, abrasion resistance and water absorption. If this waste is available locally; it can be an alternative to replacing cement and finer particle of coarse aggregate in concrete paver block.


Reference

1. Jaykumar P.T. et al. “Experimental investigation on paver block using steel slag as a partial replacement of aggregates and sludge as partial replacement of cement” International journal of science and research (IJSR).
2. Koli Nishikant et al. “manufacturing of concrete paving block by using waste glass materials.” International journal of scientific and research (2010) publication vol-6.
3. Praveen Mathew et al “steel slag ingredient for concrete pavement” International journal of innovative research in science engineering and technology(IJIRSET) vol. 2
4. Raghu Nathan et al ,”study on strength of concrete with ETP sludge from dyeing industry” International journal of civil and structural engineering.(IJCSE) vol.1
5. Sreedevi et al “Experimental investigation on the use of textile sludge in concrete” International journal of advance in engineering and technology (IJAET) Vol. 8.
6. V.Subhathradevi and B.K. Granvel “Properties of concrete manufactured using steel slag” Science Direct.
7. Recommended guidelines for concrete mix design IS 10262:2009.Bureau of Indian Standard New Delhi.
8. Plane and R/F concrete IS 456:2000 Bureau of Indian Standard New Delhi.

Dr. S P Ahirrao holds a BE from Mysore University. ME in Building Science & Technology from North Maharashtra University, Jalgaon, Ph.D. from North Maharashtra University, Jalgaon. He was head of civil engineering dept. SSVPS Polytechnic Dhule, Maharashtra He is Associate Professor at Sandip Instutie of Engineering & Management

Nasik Maharashtra He is Life member of ISTE & IEI. He has Published Technical and Research papers at National and international level of Journals and seminars.