EXPERIMENTAL STUDY OF EFFECT OF SODIUM SILICATE (NA 2 SIO 3 ) ON PROPERTIES OF CONCRETE

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1 International Journal of Civil Engineering and Technology (IJCIET Volume 6, Issue 12, Dec 2015, pp , Article ID: IJCIET_06_12_004 Available online at ISSN Print: and ISSN Online: IAEME Publication EXPERIMENTAL STUDY OF EFFECT OF SODIUM SILICATE (NA 2 SIO 3 ON PROPERTIES OF CONCRETE Ifrah Habib Lone, Abdul Muneeb, Javid Ahmad, Syed Mohammad Jasim, Mintazir Ali, Mushtaq Ahmad Khan and Amir Hussain Malik Department of Civil Engineering, University of Kashmir, India ABSTRACT This paper aims to investigate the effect of use of sodium silicate in cold weather concreting. In order to illustrate such effect, a series of laboratory tests were conducted. Workability tests, compressive strength tests, flexural tests and split tensile strength tests were carried out on concrete specimens having different percentage of sodium silicate and the results thus obtained were compared those of normal concrete. The results indicated that the Sodium silicate does not contribute to an increase in strength of concrete, rather it has reverse effects.however it does increase Compaction Factor, thereby enhancing workability of concrete. Key words: Sodium Silicate, Workability, Compressive, Flexural and Split Tensile. Cite this Article: Ifrah Habib Lone, Abdul Muneeb, Javid Ahmad, Syed Mohammad Jasim, Mintazir Ali, Mushtaq Ahmad Khan and Amir Hussain Malik, Experimental Study of Effect of Sodium Silicate (Na2sio3 on Properties of Concrete. International Journal of Civil Engineering and Technology, 6(12, 2015, pp INTRODUCTION IS 7861 part II defines Cold Weather Concreting as Any operation of concreting done at about 5 C atmospheric temperature or below. ACI 306 Cold Weather Concreting defines cold weather concreting as a period when for more than three (3 consecutive days, the following conditions exist: The average daily air temperature is less than 5 C (40 F and, The air temperature is not greater than 10 C (50 F for more than one-half of any 24 hour Winter has some peculiarities that affect construction in general and concreting in particular. Its duration is different in different parts of globe, but cold weather white frosts may also happen in spring and autumn not just in winter only. In India 39 editor@iaeme.com

2 Ifrah Habib Lone, Abdul Muneeb, Javid Ahmad, Syed Mohammad Jasim, Mintazir Ali, Mushtaq Ahmad Khan and Amir Hussain Malik certain regions experience sub-zero temperatures in winter. Concrete structures in such regions undergo cycles of freezing and thawing and their durability is affected due to frost action. Fresh concrete contains considerable quantity of fresh water which gets converted into ice lenses at freezing temperature. The ice formation in fresh concrete results in about 9% rise in volume and causes permanent damage to concrete and structural integrity cannot be recovered even if the concrete is made to harden later at high temperature. Even during hardening the concrete should be protected from extremely low temperature hence while concreting in cold weather ensure that the temperature of fresh concrete is maintained above 0 C and temperature during first six hours of casting should not be less than 5 C. Stopping the process of concreting in winter is uneconomical due to long downtimes of equipment and workers. It is better to bear additional costs and trying to minimize them as much as possible. Thus, in winters, especially in Kashmir where the temperatures are below zero degree in winters some admixtures need to be added to nullify the effects of cold temperature on the strength of concrete. Considering the availability and cost of the admixture, Sodium silicate is used as an admixture in Kashmir in winters. 2. MATERIALS USED Cement Ordinary Portland Cement (OPC 43 Grade (Safico cement confining to IS: 4031[4] has been used for this Work. The properties of the used cement are shown; Fineness Standard Initial Setting Final Setting Soundness Compressive % Consistency (% Time Time (mm strength(n/mm hr. 16 min 6 hrs. 15 min Aggregates Fine aggregates used throughout the work comprised of clean river sand maximum size of 4.75mm conforming to zone III as per IS: [5] Coarse aggregates used consisted of machine crushed stone angular in shape passing through 20mm I S sieve and retained on 4.75mm I S sieve. Sodium silicate ( : Color- Lemon-Orange Appearance-Clear bright Liquid Relative Density (g/ml-2.4 g/ml 3. EXPERIMENTAL PROGRAM Mix Used: Nominal mix M20 (1:1.5: 3 water to cement ratio of 0.5. In total four castings were done at the sodium silicate percentage of 1, 1.4, 1.8 and 2.2 First Casting Average Temp: C Percentage of sodium silicate by weight of cement = 1 % 40 editor@iaeme.com

3 Experimental Study of Effect of Sodium Silicate (Na 2 sio 3 on Properties of Concrete Compressive (σ c size(mm 7 Days 28 Days (N/mm 2 Average (N/mm 2 (N/mm 2 Average (N/mm Split Tensile (σ t and Flexural (σ b Type of concrete (σ t (N/mm 2 (σ b (N/mm 2 Slump Compaction factor PCC mm 0.71 CC sodium silicate mm 0.80 Second Casting Average Temp: C Percentage of sodium silicate by weight of cement = 1.4 % Compressive (σ c 7 Days 28 Days (N/mm 2 Average (N/mm 2 (N/mm 2 Average (N/mm 2 size(mm Split Tensile (σ t and Flexural (σ b Type of concrete Split tensile strength (N/mm 2 Flexural strength (N/mm 2 Slump Compaction factor PCC mm 0.73 CC sodium silicate mm 0.84 size(mm Third Casting Average Temp: C Percentage of sodium silicate by weight of cement = 1.8 % Compressive (σ c 7 Days 28 Days (N/mm 2 Average (N/mm 2 (N/mm 2 Average (N/mm editor@iaeme.com

4 Ifrah Habib Lone, Abdul Muneeb, Javid Ahmad, Syed Mohammad Jasim, Mintazir Ali, Mushtaq Ahmad Khan and Amir Hussain Malik Split Tensile (σ t and Flexural (σ b Type of concrete σ t (N/mm 2 σ b (N/mm 2 Slump Compaction factor PCC mm 0.75 CC sodium silicate mm 0.85 Fourth Casting Average Temp:-1 0 C Percentage of sodium silicate by weight of cement = 2.2 % Compressive (σ c size(mm 7 Days 28 Days (N/mm 2 Average (N/mm 2 (N/mm 2 Average (N/mm Split Tensile (σ t and Flexural (σ b Type of concrete σ t (N/mm 2 σ b (N/mm 2 Slump Compaction factor PCC mm 0.72 CC sodium silicate mm DISCUSSION In order to study the rate of variation of strength respect to the Sodium Silicate percentage, a comparative study of the test results achieved at different Sodium Silicate percentage is performed. Following Variations are studied Variation of decrease in 7 day strength Sodium Silicate % Variation of decrease in 28 day strength Sodium Silicate % Variation of split and flexural tensile strength Sodium Silicate % Comparison of in 7 and 28 day strength for 150mm cube Variation of compaction factor on adding Sodium Silicate. 7 Days Compressive (σ c Plain (casting I Plain (casting II Plain (casting III Plain (casting IV (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm editor@iaeme.com

5 Experimental Study of Effect of Sodium Silicate (Na 2 sio 3 on Properties of Concrete Admixture 1% (casting I (N/mm 2 (N/mm 2 Admixture 1.4% (casting II (N/mm 2 (N/mm Admixture 1.8% (casting III (N/mm 2 (N/mm Days Compressive (σ c Admixture 2.2% (casting IV (N/mm 2 (N/mm Plain (casting I Plain (casting II Plain (casting III Plain (casting IV (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm 2 (N/mm Admixture 1% (casting I (N/mm 2 (N/mm 2 Admixture 1.4% (casting II (N/mm 2 (N/mm Admixture 1.8% (casting III (N/mm 2 (N/mm Average decrease in 7 days and 28days strength (%age Admixture 2.2% (casting IV (N/mm 2 (N/mm Percentage of sodium silicate Average % decrease in 7 Average %decrease in days strength 28 days strength Average decrease in Split tensile strength (σ t and Flexural strength (σ b Percentage of sodium silicate Average percentage decrease in Split tensile strength Average percentage decrease in Flexural strength editor@iaeme.com

6 %age decrease in strength %age decrease in strength %age decrease in strength Ifrah Habib Lone, Abdul Muneeb, Javid Ahmad, Syed Mohammad Jasim, Mintazir Ali, Mushtaq Ahmad Khan and Amir Hussain Malik GRAPH 1 Average decrease in 7 day compressive strength GRAPH 2 Average decrease in split tensile strength GRAPH 3 Average decrease in flexural strength editor@iaeme.com

7 %age decrease in strength %age increase in compaction factor Experimental Study of Effect of Sodium Silicate (Na 2 sio 3 on Properties of Concrete GRAPH 4 Variation of CF %age of sodium silicate The results graphs and tables represent the comparative study: GA:Comaprison between Average decrease in 7 and 28 day compressive strength day strength 28-day strength From the study of GA it is clear that the by adding Sodium both 7 and 28 day strength for 150 mm cube decreases and reach their minimum at the sodium silicate percentage of 1.25%,the decrease in 7day strength is 214% more than increase in 28 day strength editor@iaeme.com

8 Ifrah Habib Lone, Abdul Muneeb, Javid Ahmad, Syed Mohammad Jasim, Mintazir Ali, Mushtaq Ahmad Khan and Amir Hussain Malik GB:Variation of CF plain concrete and concrete admixture st casting 2nd casting 3rd casting 4th casting CF of plain concrete Cf of concrete admixture G6 shows that the compaction factor always increases when compared the plain concrete, thus workability increases by the addition of sodium silicate. 5. CONCLUSION After analyzing the test results following important conclusions are drawn: Sodium silicate does not contribute to an increase in strength of concrete, rather it has reverse effects. The results indicated that while a hastened stiffening of the paste resulted from the admixture of sodium silicate no gain in the 1-day strength was obtained and the loss in strength at later ages was so great that it is only under exceptional conditions that the use of sodium silicate is advisable. Both 7 and 28 day strength for 150 mm cube decreases and reach their minimum at the sodium silicate percentage of 1.25%, the decrease in 7day strength is 214% more than increase in 28 day strength. However it does increase Compaction Factor, thereby enhancing workability of concrete REFERENCES [1] M.S. Shetty, Concrete Technology, Chapters 1-8,page nos , [2] IS 9103: 1999, Admixtures: definition, Page nos (23, 24. [3] IS 456 : 2000, strength of concrete: tests, compressive strength.pages (2-7 [4] Abbas S. Al-Ameeri, K.A.Al- Hussain and M.S Essa, Constructing a Mathematical Models to Predict Compressive of Concrete from Non- Destructive Testing, International Journal of Civil Engineering & Technology (IJCIET, Volume 4, Issue 4, 2013, pp. 1-20, ISSN Print: , ISSN Online: [5] Alaa Abdul Kareem Ahmad, The Effect of Gypsum Compensative on Mortar Compressive, International Journal of Civil Engineering & Technology (IJCIET, Volume 4, Issue 3, 2013, pp , ISSN Print: , ISSN Online: [6] P.J.Patel, Mukesh A. Patel and Dr. H.S. Patel, Effect of Coarse Aggregate Characteristics on Properties of High Performance Concrete using Mineral and Chemical Admixtures, International Journal of Civil Engineering & Technology (IJCIET, Volume 4, Issue 2, 2013, pp , ISSN Print: , ISSN Online: editor@iaeme.com

9 Experimental Study of Effect of Sodium Silicate (Na 2 sio 3 on Properties of Concrete [7] Dr. Shanthappa B. C, Dr. Prahallada. M. C. and Dr. Prakash. K. B., Effect of Addition of Combination of Admixtures on the Properties of Self Compacting Concrete Subjected to Alternate Wetting and Drying, International Journal of Civil Engineering & Technology (IJCIET, Volume 2, Issue 1, 2011, pp , ISSN Print: , ISSN Online: [8] M. VijayaSekhar Reddy, Dr.I.V. Ramana Reddy and N. Krishna Murthy, Experimental Evaluation of the Durability Properties of High Performance Concrete using Admixtures, International Journal of Advanced Research in Engineering & Technology (IJARET, Volume 4, Issue 1, 2013, pp , ISSN Print: , ISSN Online: [9] Vinod P, Lalumangal and Jeenu G, Durability Studies on High High Performance Concrete, International Journal of Civil Engineering & Technology (IJCIET, Volume 4, Issue 1, 2013, pp , ISSN Print: , ISSN Online: [10] Ali S. Faris, Riadh Al-Mahaidi and Awad Jadooe, Implementation of Magnetized Water To Improve The Properties of Concrete, International Journal of Civil Engineering & Technology (IJCIET, Volume 5, Issue 10, 2014, pp , ISSN Print: , ISSN Online: editor@iaeme.com