NATURAL POLYMER AS WATERPROOFING COMPOUND IN CEMENT CONCRETE

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1 NATURAL POLYMER AS WATERPROOFING COMPOUND IN CEMENT CONCRETE Remya V 1 and Hima Elizabeth Koshy 2 1,2 Assistant Professor, Department Of Civil Engineering, Mount Zion College of Engineering, Pathanamthitta Abstract Permeability of concrete becomes major concern for the durability of hydraulic and water retaining structures, because concrete is directly exposed to water or humid environment in such structures. Hence water proofing compounds can be used to improve the pore structure of concrete and hence to reduce the water permeability of concrete. The main aim of this project is to study the effect of the waterproofing compound natural polymer on durability and mechanical properties of concrete. Keywords permeability, waterproofing compounds, natural polymer, acid attack, durability I. INTRODUCTION Concrete is the widely used construction material in the various fields of industry. So it is very important to consider its durability as it has indirect effect on economy, serviceability and maintenance. In case of hydraulic and water retaining structures, concrete is directly exposed to water or humid environment. Hence, permeability of concrete becomes major concern for the durability of such structures. The damage of concrete usually proceeds from free exposed surfaces and is often caused by capillary transport processes in the pore system. Physical or chemical damage mechanisms can lead to substantial damage of concrete materials especially if they occur cyclically. Reactive gaseous or fluid media cause material deterioration or produce capillary pore pressure. More severe damage in concrete also changes the capillary pore structure and increases permeability parameters. Permeability of concrete is therefore an important performance value and its increase over time can indicate critical states. Several attempts have been made to reduce the water permeability by either adding chemicals or pozzolanic material. Water proofing admixtures and pozzolanic materials can be used to improve the pore structure of concrete and hence to reduce the water permeability of concrete. Concrete made by the modification of ordinary concrete with polymer admixture has been developed for tensile strength requirement and resistance to certain chemicals. The polymer-modified concrete has a monolithic co-matrix in which the organic polymer matrix and the cement gel matrix are homogenized. The different types of polymer concrete are; polymer impregnated concrete, polymer concrete and latex modified concrete II. SCOPE AND OBJECTIVE In case of hydraulic and water retaining structures, concrete is directly exposed to water. More severe damage in concrete changes the capillary pore structure and increases permeability. Water proofing admixtures are used to reduce the water permeability of plain concrete. In present experimental work, various water proofing chemicals are to be used in concrete to evaluate its performance and effect on properties of concrete. The water proofing admixtures was added during mixing of concrete ingredients. Natural polymer is one of the main waterproofing admixture. The main objective of this project is to evaluate the use of a natural polymer as a waterproofing compound in concrete and also to find optimum percentage of natural polymer in concrete. III. METHODOLOGY Literature review. Perform trial mixes and arrive at the optimum mix of grade M35. Selection of waterproofing compound as natural polymer DOI: /IJMTER PTNIV 128

2 Optimum percentage of natural rubber latex in concrete Permeability test, water absorption test, porosity test, acid attack test, sorptivity test and compression test are to be done. Interpretation of results: compare the results of natural and manufactured waterproofing compounds in concrete. Specimens cast are: 1) 100mmx100mmx100mm cubes 2) 100mmx50mm discs IV. EXPERIMENTAL INVESTIGATION This chapter presents the details of the experimental investigation carried out to study the workability, strength, and durability of concrete with natural polymer as waterproofing compounds. The mix design was done to obtain a compressive strength of 35 Mpa. The materials were mixed in required proportions and casting of specimens is done. The specimens were cured in water. Detailed characterization tests were conducted in the laboratory to evaluate the required properties of the individual materials. The test program include the determination of mechanical property by cube compressive strength, durability properties by acid attack test, porosity test, water absorption test and water permeability test. 4.1 Material properties The properties of each material in the concrete mix were studied at the early stage itself. Different tests were conducted for each material as specified by relevant IS codes. The ingredients used for making the various concrete mixes are OPC 53 grade cement, fine aggregate, coarse aggregate, super plasticizer, manufactured and natural waterproofing compounds. 4.2 Cement The function of cement is to act as binder between the fine aggregate and the coarse aggregates and to fill the voids in between sand and coarse aggregate particles to form a compact mass. Ordinary Portland cement of grade 53 conforming to IS: was used. Laboratory test were conducted on ordinary portland cement to determine the properties. Results are given in table 1. Table 1. Properties of ordinary Portland cement Test Results Correct value Fineness 2% Less than 10% Standard 32% 26-33% consistency Initial setting time 67 min Greater than 30 min. Specific gravity Fine aggregate Locally available river sand passing through 4.75 mm is sieve was used for the experiments. Laboratory tests were conducted to determine different physical properties as per IS 383 (part III) Sieve analysis was done to determine the grain size distribution of river sand. Table 2. Properties of fine aggregate Tests Results Specific gravity 2.6 Bulk density 1.30 g/cc Void ratio 0.6 Grading zone II Porosity 21.31% Table 3. Sieve analysis of fine All rights Reserved 129

3 Sieve International Journal of Modern Trends in Engineering and Research (IJMTER) Empty Weight with sample Weight with retained sample retained Cumulative percentage pass Pan Coarse aggregate The size of coarse aggregate between 20mm and 4.75 mm. For proper gradation, combination of 12.5 mm and 20 mm aggregates are used. Laboratory tests were conducted on coarse aggregate to determine the different physical properties as per IS 383 (part III) Table 4. Properties of coarse aggregate Tests 20mm Results 12.5mm Specific gravity Bulk density 1.55 kg/l 1.56 kg/l Void ratio Porosity 42.8% 42.9% Sieve Empty Weight with sample Table 5. Sieve analysis of fine aggregate Weight with retained sample retained Cumulative percentage pass Pan Mixing water Potable water is generally considered as being acceptable. Hence clean drinking water available was used for casting as well as curing of the test All rights Reserved 130

4 4.2.4 Natural polymer based waterproofing compound Polymers with different kinds of fillers are used as construction materials. They have good binding properties and good adhesion with aggregates. They have long-chain structure, which helps in developing long-range network structure of bonding. In contrast, cement materials provide shortrange structure of bonding. As a result, polymer materials usually provide superior compressive, tensile and flexural strength to the concrete compared to Portland cement. The properties of natural polymer are listed below Table 6. Properties of natural polymer Sl.No Property Rubber latex 1 Colour White 2 Total solid content(% by ) 61.5 max 3 Dry rubber content(% by ) 60 min 4 Non rubber solid content 1.50 max 5 KOH number 0.55 max 6 Ammonia content, nh3% 0.70 max 7 Mechanical stability time 600 to Volatile fatty acid number 0.10 max 9 Magnesium content 8 10 Ph 10.4 min 11 Coagulum content, % by mass 0.01 max 12 Sludge content, % by mass 0.01 max 13 Copper content as PPM 5 14 Iron content as PPM 8 15 Particle size of rubber latex 0.2µm 16 Specific gravity of rubber latex Mix design The final proportion was 1:1.1:2.6 (cement: fine aggregate: coarse aggregate) with w/c of The materials used for the 1m 3 concrete are given below Table 7. Materials used for 1m 3 concrete Material Quantity(kg/m 3 ) Cement 485 Fine aggregate All rights Reserved 131

5 Coarse aggregate 1261 Water 186 V. PROPERTIES OF CONCRETE 5.1 Fresh properties of concrete Workability of concrete Workability is the property of concrete which determines the amount of useful internal work necessary to produce full compaction. Slump test was done to measure the workability of concrete based on IS: Mechanical properties of hardened concrete Compressive strength of concrete The compressive strength test was carried out on cubical specimen of size 150mmx150mmx150mm in a compression testing machine of capacity 2000kN, at a loading rate of 14 N/mm 2 per minute as per IS 516:1959 specification. 5.3 Durability properties of hardened concrete Weight loss of concrete due to acid environment To check the loss of due to acid environment of concrete with different waterproofing materials, 150 mm concrete cube specimens were tested based on modified ASTM C test method. After 28 days of water curing, the concrete specimens were exposed to 5 % sulphuric acid solution for 56 days, and the surface colour change and surface deterioration were studied. The 5% sulphuric acid solution was prepared by diluting 98% concentrate sulphuric acid with water. Weights of specimens before and after acid attack were noted Strength loss of concrete due to acid environment To check the loss of strength of concrete with waterproofing material against sulphuric acid, 150 mm concrete cube specimens were tested based on modified ASTM C test method. After 28 days of water curing, the concrete specimens were exposed to 5 % sulphuric acid solution for 56 days, and the surface colour change and surface deterioration were studied. The 5% sulphuric acid solution was prepared by diluting 98% concentrate sulphuric acid with water. loss in compressive strength S 1 =average compressive strength of specimens before acid attack S 2 = average compressive strength of specimens after acid attack Water absorption of concrete Based on ASTM C 140 water absorption test were conducted for concrete with and without waterproofing compound.150 mm concrete cube specimens were used for conducting water absorption test. 28 days cured specimens were used for water absorption test. of loss= W 1 =average of specimens after air drying for 24 hours W 2 =average of specimens after water absorption Porosity of concrete 150 mm concrete cube specimens were used for conducting porosity test. 28 days cured specimens were used for water absorption test based on ASTM C of loss= W 1 =average of specimens before oven drying W 2 =average of specimens after oven All rights Reserved 132

6 5.3.5 Permeability of concrete Based on IS: permeability test were conducted for concrete with and without waterproofing compound. 100 mm concrete cube specimens were used for conducting permeability test. Where, K = Coefficient of permeability in cm/sec, Q = Quantity of water in milliliters percolating over the entire period of test after the steady state has been reached, A = Area of the specimen face in cm 2, T = Time in seconds over which Q is measured, = Ratio of the pressure head to thickness of specimen, both expressed in the same units Sorptivity of concrete Sorptivity, or capillary suction, is the transport of liquids in porous solids due to surface tension acting in capillaries. It is measured as the rate of uptake of water. Test was conducted based on ASTM C Where I is the cumulative absorbed volume after time t per unit area of inflow surface (mm 3 /mm 2 ), Mt the change in specimens mass at the time t, ρ the density of fluid, A the crosssectional area in contact with fluid. The initial sorptivity, defined in accordance with ASTM C , includes data measured from 1 minute up to 6 hours. I Where, Si is the sorptivity or the initial rate of absorption (mm/min 1/2 ) determined from the least squares linear regression. VI. CONCLUSION As a part of this study mechanical property and durability properties of concrete with waterproofing compound was analysed and also found the variation of strength with the variation in the percentage of natural rubber latex. Maximum compressive strength is obtained for concrete with 1% natural rubber latex. So 1% is selected as the optimum percentage of natural rubber latex. As compared with normal concrete, concrete with 1% natural polymer showed higher slump values. It is clear that concrete with 1% natural polymer showed better result than the normal concrete. Waterproofing compound improves the pores structure of concrete and made the concrete denser than the normal concrete and showed better result than normal concrete. Weight loss due to acid environment is greater in normal concrete. As compared with normal concrete, concrete with 1%natural polymer showed 54.13% decrease in percentage loss due to acid attack. Strength loss due to acid environment is greater in normal concrete. The strength losses of natural and manufactured concretes are comparable. As compared with normal concrete, concrete with 1%natural polymer showed 40.76% decrease in percentage strength loss due to acid attack. Compared with normal concrete, concrete with 1% natural polymer showed 42% decrease in water absorption. Compared with normal concrete, concrete with 1% natural polymer showed 58% decrease in porosity. Compared with normal concrete, concrete with 1%natural polymer showed 49.08% decrease in All rights Reserved 133

7 Compared with normal concrete, concrete with 1% natural polymer showed 41.1% decrease in sorptivity. REFERENCES [1] Anil kumar, Raghavendra and Sudha kumar, Durability characteristics of high performance concrete with ground granulated blast furnace slag, International journal of enhanced research in science technology & Engineering, Vol 4, Issue 11, 2014 [2] Dr.K.Srinivasu, M.L.N.Krishna Sai, Venkata Sairam Kumar.N, A Review on Use of Metakaolin in Cement Mortar and Concrete, International Journal of Innovative Research in Science,Vol 3,Issue 7, 2014 [3] Nimitha, Vijayaraghavan and Dr. Wayal, Effect of manufactured sand on durability properties of concrete, American journal of engineering research, Vol 2, Issue-12, pp , 2013 [4] Sudarsana Rao, Munirathnam, Ghorpade and Sashidha, Influence of natural rubber latex on permeability of fibre reinforced high-performance concrete, International journal of enhanced research in science technology & Engineering, vol 2, Issue 7, 2013 [5] Mohammad Reza and Seyed Mousavi Effects of Nano-Silica on permeability of concrete and steel bars reinforcement corrosion, Australian journal of basic and applied sciences, pp , All rights Reserved 134