INTRODUCTION:

Construction materials constitutes a major cost component in any construction project. The total cost of construction materials can be 50% or more of the total cost. The selection of a particular type of material depends mainly upon the requirement, which can be determined by several properties and characteristics of that material. The most considerable factors of a material can be its cost, strength and its adaptability to the project. Here, we are considering few construction materials like Brick, Cement and Flooring types and arriving at a reasonable decision considering all the others influencing factors. Now-a-days, in each considered materials there are various types i.e, in bricks we are considering Burnt Clay Bricks, Flyash Blocks, AAC Blocks, CLC Block, Flyash Lime bricks and Flyash Cement bricks. In the same way, the types of cement we have considered are OPC, PPC [Flyash based], RHPC, PSC; While in flooring materials we have Granite, Marble, Sandstone, Slate and Limestone. By adopting the MADM Approach, the large variations in the performance of different types of materials with respect to various attributes render the selection of suitable type of Brick, Cement and Flooring material as a problem for engineers.

AIM:

The aim of the project is to select an appropriate construction material by studying, analyzing and normalizing the properties by using SAW Method with respect to the MADM approach, which is a Decision-Making Tool.

In market, we can find various types of construction materials with diverse properties; hence it has become a major problem to analyse a suitable and appropriate material. Initially, the perspective of the customers was mainly about economy, but today the thought process is changing. People are considering several attributes in choosing a material according to their need and requirement. But choosing a material by considering all the factors is becoming difficult. So, in order to overcome such difficulty a simple method of MADM Approach i.e, Simple Additive Weighing can be used. Here, in this method we Normalise the different properties of various materials and choose a highly performing type of material with regard to all the attributes.

LITERATURE STUDY:

MULTIPLE ATTRIBUTE DECISION MAKING (MADM) METHODS:

Multiple Criterion Decision Making (MCDM) refers to making decisions in the presence of multiple, usually conflicting criteria. The MCDM problems can be broadly classified into two categories: Multiple Atribute decision making (MADM) and Multiple Objective Decision Making (MODM), depending on whether the problem is a selection problem or a design problem. MODM methods have decision variable values that are determined in a continues or integer domain, with either an infinite or large number of choices, the best of which should satisfy the decision maker’s constraints and preference and priorities. MADM methods on the other hand, are generally discrete, with a limit number of pre-determined alternatives. MADM is an approach employed to solve problems involving selection from a finite number of alternatives. An MADM method specifies how attributes informations is to be proceeded in order to arrive at a choice. MADM method requires both inter and intra attribute comparisons and involves appropriate explicit tradeoffs. Of the many MADM methods reported in the literature a few important methods that have a higher potential to solve decision making problems are: Simple Additive Weighing (SAW), Weighted Product Method (WPM), Analytic Hierarchy Process (AHP), Revised Analytic Hierarchy Process (RAHP), Multiple Analytic Hierarchy Process (MAHP), TOPSIS Method, etc. It is beyond the scope of a paper to discuss all methods of MADM.

SIMPLE ADDITIVE WEIGHTING (SAW):

This is also called as the weighted sum method. It is the simplest and still the widest used MADM method. Here each attribute is assigned a weight and sum of all weights must be 1. Each alternative is assessed with regard to each attribute. Here, let us consider, one of the important basic requirements is economy, which is related to the cost and life span of the material. It is required to convert the value of cost and life between ‘0’ to ‘1’, so that these values can be compared to each other. Among these properties, cost of a material is non beneficial, while life span of a material is beneficial. As, cost is non-beneficial, minimum cost of a material is assigned ‘1’ value. The cost of other pipes is converted accordingly in reference to ‘1’ value. In contrast, life span of a material is beneficial and the one, which has the longest life span among all types of materials is assigned as ‘1’ and the values for other materials are assigned in reference to ‘1’. By using SAW method the most suitable material can be determined.

METHODOLOGY:

Churchman and Ackoff (1954) first utilized the SAW method to cope with a portfolio selection problem. The SAW method is probably the best-known and widely used method for multiple attribute decision making MADM. Because of its simplicity, SAW is the most popular method in MADM problems and the best alternative can be derived by the following equation:

 A*ux|max u_ix|i1, 2... n}

Or the gaps of alternatives can be improved to build a new best alternative A* for achieving aspired/desired levels in each criterion. Here,ui(x) denotes the utility of the i^thalternative and i = 1,2...n; wj denotes the weights of the j^th criterion; rij(x) will be the normalized preferred ratings of the i^th alter- native with respect to the j^th criterion for all commensurable units; and all criteria are assumed to be independent. In addition, the normalized preferred ratings (rij(x)) of the i^th alternative with respect to the j^th criterion can be defined by:

· For benefit criteria where larger value is better i.e., r_ij (x)=x_ij/x_j*, where x_j*=max_ix_ij or let x_j* be the aspired/desired level, and it is clear 0<=r_ij (x)<=1.

· For cost criteria where smaller value is better i.e., r_ij (x)=(1/x_ij)/(1/xj*)=(max_i x_j*)(x_ij) or let x_j* be aspired/desired level. [1]

Therefore, we obtain the high performance value or rank of each and every material we are considering. Next, few materials like cement, brick and flooring materials are taken into consideration to demonstrate the procedure of SAW in determining the preferred order of alternatives.

INVESTIGATIONS:

To acquire the properties of different types of cements, Bricks and Flooring materials we have referred the Indian Standard Code Books and different Journals & Research Papers. The codebooks, which we have referred for cements are IS 269:2013, IS 1489:1991, IS 8041:1990, IS 455:1989. As the properties are all independent in nature we can further proceed with the normalization. According to this method, we are giving the value to the Qualitative terms, so that it becomes easy for further calculations.

Table 1: Different types of cements with their properties

(The physical properties of materials are taken from Reference Number 2)

PROPERTIES [2]	OPC (IS 269:2013)	PPC [Flyash Based] (IS 1489.1:1991)	RHPC (IS 8041:1990)	PSC (IS 455:1989)
Fineness	Min 225 sq.mt/kg	Min 300 sq.mt/kg	Min 325 sq.mt/kg	Min 225 sq.mt/kg
Soundness	Max 10mm	Max 10mm	Max 10mm	Max 10mm
Compressive Strength	· 72±1h, Min 16MPa · 168±2h, Min 22MPa · 672±4h, Min 33MPa Max 48MPa	· 72±1h, Min 16MPa · 168±2h, Min 22MPa · 672±4h, Min 33MPa	· 24±30min Min 16MPa · 72±1h, Min 27MPa	· 72±1h, Min16MPa · 168±2h,Min 22MPa · 672±4h, Min 33MPa
Setting Time	Min 30 min Max 600 min	Min 30 min Max 600 min	Min 30 min Max 600 min	Min 30 min Max 600 min
Bulk Density	830 kg/cu.m to 1650 kg/cu.m.	700 kg/cu.m to 1300 kg/cu.m.	830 kg/cu.m to 1300 kg/cu.m.	1000 kg/cu.m to 1200 kg/cu.m.
Cost	Rs.375 per 50kg bag	Rs.370 per 50kg bag	Rs.330 per 50kg bag	Rs.360 per 50kg bag
Specific Gravity	3.15	3.00	3.00	3.07
Eco friendliness	Minimum	Maximum	Moderate	Maximum
Heat of Hydration	Minimum	Moderate	Maximum	Minimum

Table 2

QUALITATIVE TERMS	VALUE
Minimum	2
Moderate	6
Maximum	10

Table 3:Normalized Values

PROPERTIES	OPC	PPC [Flyash Based]	RHPC	PSC
Fineness	0.692	0.923	1.000	0.692
Soundness	1.000	1.000	1.000	1.000
Compressive Strength	0.593	0.593	1.000	0.593
Setting Time	1.000	1.000	1.000	1.000
Bulk Density	1.000	0.806	0.859	0.887
Cost	0.880	0.892	1.000	0.917
Specific Gravity	1.000	0.952	0.952	0.975
Eco-Friendliness	1.000	0.600	0.200	1.000
Heat of Hydration	1.000	0.333	0.200	1.000

Table 4:Summarization of all different cements with their properties, weights and ranked by saw method

PROPERTIES	Weights	OPC	PPC [Flyash Based]	RHPC	PSC
Fineness	0.05	0.692	0.923	1.000	0.692
Soundness	0.05	1.000	1.000	1.000	1.000
Compressive Strength	0.25	0.593	0.593	1.000	0.593
Setting Time	0.07	1.000	1.000	1.000	1.000
Bulk Density	0.15	1.000	0.806	0.859	0.887
Cost	0.23	0.880	0.892	1.000	0.917
Specific Gravity	0.05	1.000	0.952	0.952	0.975
Eco-Friendliness	0.05	1.000	0.600	0.200	1.000
Heat of Hydration	0.1	1.000	0.333	0.200	1.000
	1.000	0.855	0.751	0.856	0.846
Rank of Preference		2	4	1	3

ANALYSIS:

Here, in the case of the cements we are considering the Heat of Hydration values with respect to its fineness respectively. The value of the quantitative terms are normalized easily, while to convert qualitative term into quantitative term, a range of values are decided and assigned a particular value to each qualitative term. It is not necessary to normalize these values. But in this paper, we are normalizing the values also, to obtain a precise result. After normalizing, we assign weightages depending on the common requirement and assign the SAW method. Here we can see the Rank of Preference where RHPC is in the first rank and OPC in the second.

Table 5: Different types of bricks with their properties

(Cost of the materials are taken from Reference Number 5)

Properties	Burnt clay bricks	Fly ash bricks	Hollow Blocks	AAC blocks	CLC blocks	Rice husk ash lime bricks	Rice husk ash cement bricks
Eco Friendliness	Low	Moderate	Moderate	High	High	Very High	High
Ease of Working	Normal	Easy	Difficult	Easy	Easy	Easy	Normal
Insulation (W/mk)	0.81	0.185	1.100	0.16	0.151	0.975	0.895
Fire Resistance	Low	Very High	High	High	Very High	High	High
Cost (per cu.m.) [5]	2288	2500	3000	2025	3200	2000	2200
Compressive Strength (kg/cm²)	32.5	95	35	40	35	39	42.5
Water absorption %	17.5	15	<10	11	11.5	12	11
Efflorescence	Slight to moderate	Moderate	Slight	Nil	Nil	Nil	Nil
Density (kg/cu.m.)	1900	1570	1437	700	800	1825	1800
Dry shrinkage	0.10	0.15	0.035	No shrinkage	No shrinkage	0.05-0.08	0.1

Table 6

(The qualitative values are taken from Reference number 3)

Qualitative Terms [3]			VALUE
Very High	Nil	Easy	10
High	Slight	Normal	7
	Moderate		4
Low	No Shrinkage	Difficult	1

Table 7: Normalized values

Properties	Burnt clay bricks	Fly ash bricks	Hollow Blocks	AAC blocks	CLC blocks	Rice husk ash lime bricks	Rice husk ash cement bricks
Eco Friendliness	0.100	0.400	0.400	0.700	0.700	1.000	0.700
Ease of Working	0.700	1.000	0.100	1.000	1.000	1.000	0.700
Insulation	0.736	0.168	1.000	0.145	0.137	0.886	0.814
Fire Resistance	0.100	1.000	0.700	0.700	1.000	0.700	0.700
Cost	0.874	0.800	0.667	0.988	0.625	1.000	0.909
Compressive Strength	0.342	1.000	0.368	0.421	0.368	0.411	0.447
Water absorption %	0.571	0.667	1.000	0.909	0.870	0.833	0.909
Efflorescence	0.550	0.400	0.700	1.000	1.000	1.000	1.000
Density	1.000	0.826	0.756	0.368	0.421	0.961	0.947
Dry shrinkage	0.100	0.150	0.350	1.000	1.000	0.065	0.100

Table 8: Summarization of all different bricks with their properties, weights and ranked by saw method

Properties

Weights

Burnt clay bricks

Fly

ash bricks

Hollow Blocks

AAC blocks

CLC blocks

Rice husk ash lime

bricks

Rice husk

ash cement

bricks

Eco Friendliness	0.08	0.100	0.400	0.400	0.700	0.700	1.000	0.700
Ease of Working	0.05	0.700	1.000	0.100	1.000	1.000	1.000	0.700
Insulation	0.05	0.736	0.168	1.000	0.145	0.137	0.886	0.814
Fire Resistance	0.06	0.100	1.000	0.700	0.700	1.000	0.700	0.700
Cost	0.22	0.874	0.800	0.667	0.988	0.625	1.000	0.909
Compressive Strength	0.24	0.342	1.000	0.368	0.421	0.368	0.411	0.447
Water absorption %	0.07	0.571	0.667	1.000	0.909	0.870	0.833	0.909
Efflorescence	0.06	0.550	0.400	0.700	1.000	1.000	1.000	1.000
Density	0.14	1.000	0.826	0.756	0.368	0.421	0.961	0.947
Dry shrinkage	0.03	0.100	0.150	0.350	1.000	1.000	0.065	0.100
	1.000	0.576	0.757	0.592	0.678	0.609	0.790	0.740
Rank of Preference		7	2	6	4	5	1	3

ANALYSIS:

Here, in the case of bricks, we have considered various types, constituting of various compositions. In such a case finding a high performing brick is typical. But SAW method made it easy to find a brick by its performance, that is taken by the weightages. By multiplying the normalized values with the weightages we obtain the actual value of the material with respect to the property. The sum of all such values helps to determine the Rank. Here, the First Rank is given to Rice husk Ash Lime Bricks where its Eco-friendliness and cost are effective in nature when compared to others.

Table 9: Different types of flooring materials with their properties [4]

BASIC REQUIREMENTS	PROPERTIES	GRANITE	MARBLE	SANDSTONE	LIMESTONE	SLATE
	Cost	(360-2300)/ sqm	(500-3330)/sqm	(160-3246)/sqm	(439-1441)/sqm	(263-4141)/sqm
Water Absorption (weight %)	Typical Range	0.01 – 0.8	0.04 – 0.8	0.3 - 12	0.08 - 26	0.3 - 6
Water Absorption (weight %)	Standard	0.4	0.2	8	3	0.45
	Typical Abrasion Resistance Index (Ha)	50 - 150	15 - 50	04 - 24	< 1 - 20	4 - 20
Strength	Typical Compressive Strength Range (MPa)	100 - 300	80 - 150	10 - 120	4 - 150	25 – 200
Strength	Typical Flexural Strength Range (MPa)	30 - 36	6 - 22	3 - 15	2 - 21	50 - 15
Durability	Weight Loss(%)	< 0.1	0.1 – 1.0	01 - 05	06 – 10	> 10
	Grade	AA	A	B	C	D
	Environment Suitability	Aggressive environments, constant wetting and drying and exposure to salt attack	Exposed to continual wetting and drying or moderate salt attack	Exposed to intermittent wetting and drying or moderate level salt attack	Exposed to intermittent wetting and drying or low level salt attack	Suitable only for use in sheltered locations free from exposure to salt attack. Additional engineering practices may be required to protect stone

TABLE 10

GRADE	VALUE
AA	2
A	4
B	6
C	8
D	10

TABLE 11: DIFFERENT TYPES OF FLOORING MATERIALS WITH THEIR TYPICAL RANGE AND STANDARD OF WATER ABSORBTION (WEIGHT %)

BASIC REQUIREMENT	PROPERTIES	GRANITE	MARBLE	SANDSTONE	LIMESTONE	SLATE
Water Absorption (weight %)	Typical Range	0.031	0.032	0.472	1.000	0.242
Water Absorption (weight %)	Standard	0.050	0.025	1.000	0.375	0.056

NORMALIZATION OF THE VALUE OF TABLE 11

BASIC REQUIREMENT	PROPERTIES	GRANITE	MARBLE	SANDSTONE	LIMESTONE	SLATE
Water Absorption (weight %)	Typical Range	0.015	0.016	0.236	0.500	0.121
Water Absorption (weight %)	Standard	0.025	0.013	0.500	0.186	0.028
		0.040	0.029	0.736	0.686	0.149

TABLE 12: DIFFERENT TYPES OF FLOORING MATERIALS WITH THEIR TYPICAL COMPRESSIVE AND FLEXURAL STRENGTH RANGES

BASIC REQUIREMENT	PROPERTIES	GRANITE	MARBLE	SANDSTONE	LIMESTONE	SLATE
Strength	Compressive Strength	1.000	0.575	0.325	0.385	0.563
Strength	Flexural Strength	1.000	0.424	0.273	0.348	0.985

NORMALIZATION OF THE VALUE OF TABLE 12

BASIC REQUIREMENT	PROPERTIES	GRANITE	MARBLE	SANDSTONE	LIMESTONE	SLATE
Strength	Compressive Strength	0.500	0.288	0.163	0.193	0.282
Strength	Flexural Strength	0.500	0.212	0.137	0.174	0.493
		1.000	0.500	0.300	0.367	0.775

TABLE 13: NORMALIZED VALUES

BASIC REQUIREMENTS	GRANITE	MARBLE	SANDSTONE	LIMESTONE	SLATE
Cost	0.710	0.491	0.552	1.000	0.430
Water Absorption (weight %)	0.040	0.029	0.736	0.686	0.149
Typical Abrasion Resistance Index (ha)	1.000	0.325	0.140	0.105	0.120
Strength	1.000	0.500	0.300	0.367	0.775
Durability	1.000	0.500	0.333	0.250	0.200

TABLE 14: SUMMARIZATION OF ALL DIFFERENT FLOORING MATERIALS WITH THEIR PROPERTIES, WEIGHTS AND RANKED BY SAW METHOD

BASIC REQUIREMENTS	WEIGHTS	GRANITE	MARBLE	SANDSTONE	LIMESTONE	SLATE
Cost	0.200	0.710	0.491	0.552	1.000	0.430
Water Absorption (weight %)	0.120	0.040	0.029	0.736	0.686	0.149
Typical Abrasion Resistance Index (ha)	0.150	1.000	0.325	0.140	0.105	0.120
Strength	0.250	1.000	0.500	0.300	0.367	0.775
Durability	0.280	1.000	0.500	0.333	0.250	0.200
	1.000	0.8268	0.415	0.390	0.460	0.372
Rank of Preference		1	3	4	2	5

ANALYSIS

Here, from the table we can see that the first priority with respect to the performance is given to Granite, where we can see its properties like abrasion resistance, strength and the durability values are high. Hence, this material satisfies the requirement in all the aspects.

CONCLUSION

By using SAW method, the most suitable materials are RHPC, Rice Husk Ash Lime Bricks and Granite. The RHPC and the Rice Husk Ash Lime Bricks are unfamiliar to most of the people. The result of these methods is highly dependent on the weightage of attributes given by the experts and it may vary from project to project. These methods may be used for selection materials in big projects, to justify choice of the material and to increase confidence in the selection of the material in the system.

REFERENCES

1. Multiple Attribute Decision Making-Methods and applications by Gwo-hshiung Tzeng and Jih-Jeng Huang

2. Indian Standard Codebooks

3. www.Construction.org

4. http://www.stonemtg.com.au/index.html

5. Standard Schedule of Rates By CPWD

Received on 16.11.2015 Accepted on 26.12.2015

Int. J. Tech. 5(2): July-Dec., 2015; Page 181-186

DOI: 10.5958/2231-3915.2015.00018.8