3/22/2016Mix Design For Concrete Roads As Per IRC:152011 engineeringcivil.com http://www.engineeringcivil.com/mixdesignforconcreteroadsasperirc152011.html Mix Design For Concrete Roads As Per IRC:152011 By Kaushal Kishore, Materials Engineer, Roorkee ABSTRACT: The stresses induced in concrete pavements are mainly flexural. Therefore flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. A simple method of concrete mix design based on flexural strength for normal weight concrete mixes is described in the paper. INTRODUCTION: Usual criterion for the strength of concrete in the building industry is the compressive strength, which is considered as a measure of quality concrete. However, in pavement constructions, such as highway and airport runway, the flexural strength of concrete is considered more important, as the stresses induced in concrete pavements are mainly flexural. Therefore, flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. It is not perfectly reliable to predict flexural strength from compressive strength. Further, various codes of the world specified that the paving concrete mixes should preferably be designed in the laboratory and controlled in the field on the basis of its flexural strength. Therefore, there is a need to design concrete mixes based on flexural strength. The type of aggregate can have a predominant effect, crushed rock aggregate resulting in concrete with higher flexural strength than uncrushed (gravel) aggregates for comparable mixes, assuming that sound materials are used. The strength of cement influences the compressive and flexural strength of concrete i.e. with the same watercement ratio, higher strength cement will produce concrete of higher compressive and flexural strength. MIX DESIGN DETAILS IRC: 152011 specified that for concrete roads OPC should be used. This code also allowed PPC as per IS: 1489 (Part1) with flyash content not more than 20 percent by weight of PPC. Accordingly OPC + fly ash may be used in concrete roads. Flyash shall be not more than 20 percent by weight of cementitious material. However, IS: 4562000 specified that fly ash conforming to grade1 of IS” 3812 may be used as part replacement of OPC provided uniform blended with cement is essential. The construction sites where batching plants are used this may be practicable. In ordinary sites where mixer or hand mixing are done uniform blending of fly ash with cement is not practicable. At such construction sites, PPC may be used. PPC should be used with caution where rapid construction methods like slip form is being used. Joints cutting also need early strength. 1 Characteristic Flexural Strength at 28 days : 4.5 N/mm2 2 Cement : Three mixes are to be designed http://www.engineeringcivil.com/mixdesignforconcreteroadsasperirc152011.html 1/11 July months.50 40 mm slump at pour the concrete will be transported from central batching plant through transit mixer. http://www.5 N/mm2.html 2/11 . 4 Maximum nominal size of aggregates : 31. Specific Gravity : 3.00 MIXB With OPC43 Grade conforming to IS: 81121989. Fine Aggregate.5 n/mm2. Fly ash 20% maximum by weight of cementations material (a) For OPC 0.20 Note: Requirements of all the three mixes are the same.engineeringcivil.45 (b) For PPC 0. Fly ash in it 20% maximum by weight of total cementitious materials (c) OPC + Fly ash mix OPC shall not be less than 340 kg/m3.5 mm Crushed aggregate 5 Fine aggregate and coarse aggregate grading : Given in Table 1 6 Minimum cement content for 4. The average temperature last year during these months was 300C. 7 days strength 40. Maximum free W/C Ratio : Workability : 7 8 (b) PPC shall not be less than 425 kg/m3. at a distance of 15 Km during June. 3 Fly ash replacement : 20% Fly ash is required to be replaced with the total cementitious materials.5 N/mm2 characteristic flexural strength: : (a) OPC shall not be less than 360 kg/m3.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 MIXA With PPC (Flyash 18 percent based) conforming to IS:1489partI1991.15 MIXC With OPC of MixB and Fly ash conforming to IS:3812 (PartI)2003 Specific Gravity : 2. Specific Gravity : 3.com/mixdesignforconcreteroadsasperirc152011. 7 days strength 37. Coarse Aggregate and Retarder Super plasticizer are the same for all the three mixes. 3 N/mm2 at 28 days age 4. B and C free W/C ratio with crushed aggregate and required average flexural target strength of 5.5 + 1.65 0. 1 Curve D found to be 0. the manufacturer of Retarder Super plasticizer recommends dosages of 1% bw of OPC. B and C mixes S = S+ Zq =4.5 0. Properties of aggregates Tests Specific Gravity Water Absorption % Fine aggregate Aggregate 1 Aggregate 2 2.96 x 0. With the given requirements and materials.com/mixdesignforconcreteroadsasperirc152011.3 N/mm2 at 28 days from Fig. For fly ash included cement dosages will be required to be adjusted by experience/ trials.40 (b) PPC 425 kg/m3 TEST DATA FOR MATERIALS AND OTHER DETAILS 1.5 3. 2.65 2.50 for PPC. assume from Fig.2% maximum by weight of cementitious material 14 Values of Z x (for National Highway) : 1. 1 http://www. which will reduce 15% of water without loss of workability. 1 & 2 aggregates are as given in Table.engineeringcivil. 1.96 x 0. The grading of fine aggregate. Note: In absence of cement strength.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 9 Exposure condition : Moderate 10 Method of placing : Fully mechanised construction 11 Degree of supervision : Good 12 Maximum of cement content : (a) OPC 425 kg/m3 13 Chemical admixture : Retarder Super plasticizer conforming to IS:91031999.8 0. but cement conforming to IS Codes.html 3/11 .65 2. This is lower than specified maximum W/C ratio value of 0. For Mix A.42. Target average flexural strength for all A.45 for OPC and 0.40 = 5. 15) = 153 kg/m3 c) PPC = 153/0. kg/m3 Note: The exact density may be obtained by filling and fully compacting constant volume suitable metal container from the trial batches of calculated design mixes. At the time of concreting. percent. Um =10 x Ga (100 – A) + C m (1 – Ga/Gc) – Wm (Ga – 1) =10 x 2.5% For 31. SSD Gc=Specific gravity of cement. The mix be altered with the actual obtained density of the mix.15 for OPC and 3.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 Curve C and D for OPC 43 Grade Take curves C and D for PPC. Other data’s: The Mixes are to be designed on the basis of saturated and surface dry aggregates.5 mm maximum size of aggregate There is always entrapped air in concrete.65/3.com/mixdesignforconcreteroadsasperirc152011.65 (100 – 1. 2/3×170 + 1/3×200= 180 kg/m3 From trials it is found that Retarder Super plasticizer at a dosages of 1.00) – 153 (2. 5.26 = 476 kg/m3 http://www. If it carries surface moisture this is to be deducted from the mixing water and if it is dry add in mixing water the quantity of water required for absorption.42 = 364 kg/m3 (Required minimum PPC is 425 kg/m3) d) Formula for calculation of fresh concrete weight in kg/m3 Um = 10 x Ga (100 – A) + C m(1 – Ga/Gc) – Wm (Ga – 1) Where. The weight of aggregates are also adjusted accordingly. Take exact value of air as obtained in the test Wm=Mixing water required in kg/m3 Cm=Cement required.42 for first trial.00 for PPC (Fly ash based) A=Air content.45 = 824 kg/m3 Aggregate 1 = 1831 x 0.3% bw of PPC may reduce 15% water without loss of workability Then water = 180 – (180 x 0.5 mm maximum size of aggregate. Therefore ignoring entrapped air value as NIL will lead the calculation of higher value of density.5) + 425(1 2. in absence assume 3. DESIGN OF MIXA WITH PPC a) Free W/C ratio for the target flexural strength of 5. as PPC is being manufactured in minimum of 43 Grade of strength. Um=Weight of fresh concrete kg/m3 Ga=Weighted average specific gravity of combined fine and coarse aggregate bulk. b) Free water for 40 mm slump from Table 2 for 31.29 = 531 kg/m3 Aggregate 2 = 1831 x 0.engineeringcivil. Assume for trial entrapped air 1.3 N/mm2 as worked out is 0.html 4/11 .65 1) =2409 kg/m3 e) Aggregates = 2409 – 425 – 153 = 1831 kg/m 3 f) Fine aggregate = 1831 x 0. Determine actual value. moisture content of site aggregates are to be determine. 5% bw of cementitious material = 6.525 kg/m3 MIX B WITH OPC a) Water = 180 – (180 x 0.45 = 854 kg/m3 e) Thus for 4.450 kg/m3 Note: http://www.5 N/mm2 flexural strength quantity of materials per cu.5) + 364 (1 – 2. (1) Water as worked out earlier = 153 kg/m3 (2) OPC = 344 kg/m3 (3) Fly ash = 86 kg/m3 Density = 10 x 2.5) + 430 (1 – 2.45 x 1827 = 822 kg/m3 (5) Aggregate (1) 0.m.00) – 153 (2.26 = 494 kg/m3 Fine Aggregate = 1899 x 0.29 = 551 kg/m3 Aggregate 2 = 1899 x 0.5 N/mm2 flexural strength quantity of materials per cu.26 x 1827 = 475 kg/m3 (7) Retarder super plasticizer 1.20 = 86 kg/m3 Mix on the basis of SSD Aggregates.3% bw of PPC = 5.65 (100 – 1.65 (100 – 1.42 = 364 kg/m3 c) Density: 10 x 2.engineeringcivil.640 kg/m3 MIXC WITH OPC + FLY ASH With a total cementitious material of 430 kg/m3. OPC = 430 x 0.com/mixdesignforconcreteroadsasperirc152011.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 g) Thus for 4.65/3.65 – 1)= 2416 kg/m3 d) Total Aggregates = 2416 – 364 – 153 = 1899 kg/m3 Aggregate 1 = 1899 x 0.80 = 344 kg/m3 Fly ash = 430 x 0.65/3.29 x 1827 = 530 kg/m3 (6) Aggregate (2) 0.html 5/11 .65 – 1) = 2410 kg/m3 Total Aggregates = 2410 – 153 – 344 – 86 = 1827 kg/m 3 (4) Fine aggregate 0.15) – 153 (2.m of concrete on the basis of SSD aggregates are given below: Water = 153 kg/m3 OPC = 364 kg/m3 Fine Aggregate (sand) = 854 kg/m3 Aggregate (1) = 551 kg/m3 Aggregate (2) = 494 kg/m3 Retarder Super Plasticizer 1% bw OPC = 3.15) = 153 kg/m3 b) OPC = 153/0. of concrete on the basis of saturated and surface dry aggregates: Water = 153 kg/m3 PPC = 425 kg/m3 Fine Aggregate (sand) = 824 kg/m3 Aggregate (1) = 531 kg/m3 Aggregate (2) = 476 kg/m3 Retarder Super Plasticizer 1. 3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 (1) Cementitious material worked out as per IRC : 152011.html 6/11 . ‘B’ and ‘c’ are given below: Materials Water kg/m3 PPC kg/m3 OPC kg/m3 Flyash kg/m3 Fine Agg. its actual density is to be determined. The mix proportions shall then be worked out accordingly including the water content.356 http://www.5 N/mm2 flexural strength quantity of material per cu.450 0. For 4. (2) kg/m3 Retarder Super plasticizer kg/m3 W/ Cementitious ratio MIX. ‘C’ with OPC+Flyash 153 153 153 425 — — — 364 344 — — 86 824 854 822 531 551 530 476 494 475 5.36 0. (3) The mix proportions given in this paper are for first trial and to be adjusted as per actual site materials. ‘B’ with OPC Mix.42 0. (2) After the first trial mix.640 6.engineeringcivil. the dosages of Retarder SP for required workability keeping the free w/c ratio with in the permissible limits and adjusting it according to the required flexural strength. which specified: In case fly ash (as per IS: 3912 Part 1) is blended at site. (1) kg/m3 Agg. kg/m 3 Agg.com/mixdesignforconcreteroadsasperirc152011. conditions and requirements. ‘A’ with PPC Mix. as specified elase where in this paper.525 3. the quantity of fly ash shall be restricted to 20 percent by weight of cementitious material and the quantity of OPC in such a blend shall not be less than 340 kg/m3 .m of concrete on the basis of saturated and surface dry aggregates of Mix ‘A’. in case of small size projects. BIS. it is the flexural strength rather than the compression strength of concrete which determine the degree of cracking and thus the performance of road. When water reduces shrinkage and porosity of concrete are reduces which provides the durability to concrete structures. If this is found by trial then take reduce water for calculation.93 kg of CO2. 2. If the trial mixes does not gives the required properties of the mix. Thus the production of 200 million tonnes of cement had emitted 200 x 0. 7. REFERENCES: 1 IS : 383 1970 Specifications for coarse and fine aggregates from natural sources for concrete (second revision) BIS. Every efforts therefore are necessary to prevent pollution on top priority basis. soil. it is desirable that their design is based on the flexural strength of concrete. India is facing serious air. Where fcr is the flexural strength in MPa or N/mm2 and fck is the characteristic compressive strength in MPa or N/mm2 as per IS: 4562000.com/mixdesignforconcreteroadsasperirc152011.engineeringcivil. With the use of superplasticizer the saving in OPC is 65 kg/m3 and water 27 lit/m3. As per IRC: 152011. food and noise pollution problems. In the financial year 20092010 India has produces 200 million tonnes of cement.html 7/11 . CONCLUSION 1. 3. 3.5 N/mm2 flexural strength concrete having same material and requirement.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 Note: 1. and it is imperative to control the quality on the basis of flexural strength. however. 6975000 tonnes of CO2 will be prevented to be emitted to the atmosphere. For pavings. when the experiences grows with the particular set of materials and site conditions very few trials will be required. New Delhi 3 IS: 9103 Specification for admixtures for concrete (first revision) BIS. New Delhi 2 IS: 4562000 Code of practice for plain and reinforced concrete (fourth revision). PPC reduces 5% water demand. in such cases. New Delhi http://www. For exact W/C ratio the water in admixture should also be taken into account. and a expert of such site very rarely will be required a 2nd trial. but without water reducer. water. where facilities for testing beams with three print loading are not available. As the stress induced in concrete pavements are mainly flexural. However. 3750000 KL of potable water will be saved and the saving of Rs.93 = 186 million tonnes of CO2 to the atmosphere. In India one kg of cement produce emitted 0. For 4. it is then required to be altered accordingly.42 = 429 kg/m3 2. 5. 4. the mix design may be carried out by using compressive strength values and there after flexural strength will be determined as per correlation between flexural strength with compressive strength given the following equation. 3300 crores per year to the construction Industry. the OPC required will be 180/0. The benefits in the uses of water reducers not limited to this. If 50 million tonnes cement in making concrete uses Water Reducers 7500000 tonnes of cement can be saved. The quality of concrete is normally assessed by measuring its compressive strength. 6. “Mix Design for Pumped Concrete”. density. Proceeding of the International Conference on Road and Road Transport Problems ICORT. (Third revision). “Concrete Mix Design with Fly Ash & Superplasticizer”. Bulletin of Indian Concrete Institute No. 51. Indian Construction. pp. 19. New Delhi 8 IRC: 152011 – Standard specifications and code of practice for construction of concrete road (Fourth revision) 9 Kishore Kaushal. 49. 1992. July September. pp. 1995. pp. 10 Kishore Kaushal. “Mix Design Based on Flexural Strength of AirEntrained Concrete”. 1988. 16 17 16 Kishore Kaushal. INDIAN HIGHWAYS. BIS. 3137 14 Kishore Kaushal. 59. pp. “Concrete Mix Design Simplified”. January. 4450. 1990. 1988. No. Journal of Central Board of Irrigation and Power. No.2530. pp. 11 Kishore Kaushal. April. 2006. pp. 18 Kishore Kaushal. Singapore. 2526. Specific gravity. New Delhi 6 IS: 3812 (PartI) 2003 Specification for pulverized fuel ash: PartI for use as pozzolana in cement. voids. 296305. 12 Kishore Kaushal. Journal of the National Building Organization. 8192 15 Kishore Kaushal. February. November.html 8/11 . “Concrete Mix Design with Fly Ash”. 56. “Method of Concrete Mix Design Based on Flexural Strength”. pp.2. 2931 17 Kishore Kaushal. 1215 December. 13 Kishore Kaushal. Vol. 9397. New Delhi.engineeringcivil. http://www. CE & CR October. pp. 1991. Indian Concrete Institute Bulletin No. 2930 19 Kishore Kaushal. ICI Bulletin No. Vol. pp.com/mixdesignforconcreteroadsasperirc152011. New Delhi 7 IS: 1489 PartI 1991 Specifications for portland pozzolana cement (PartI) Flyash based. pp. “Concrete Mix Design Based on Flexural strength for AirEntrained Concrete”. “HighStrength Concrete”.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 1999 4 IS: 8112 1989 Specifications for 43 Grade ordinary portland cement (first revision) BIS. April June 1997. The Indian Concrete Journal. BIS. April. “Concrete Mix Design Containing Chemical Admixtures”. Proceeding of 13th Conference on our World in Concrete and Structures. AprilJune. 1995. “ Mix Design for Pumped Concrete”. 11. 1996. absorption and bulking. cement mortar and concrete (second revision) BIS. New Delhi 5 IS: 2386 (PartIII) 1963 method of test for aggregate for concrete. 1989. “Concrete Mix Design for Road Bridges”. 112. August. 1: Grading of Aggregates IS Sieve Designation Percentage of passing by mass Fine aggregate from river 26. Maximum size of aggregate (mm) Type of aggregate Slump (mm) Uncrushed http://www.com/mixdesignforconcreteroadsasperirc152011.0 mm 9.50 mm 4.75 mm 600 micron 150 micron 75 micron Combined grading of mix IRC: 152011 recommended grading of combined aggregates for pavement quality concrete (PQC) (1) (2) 29% 26% 100 100 100 100 100 100 100 98 99 85 – 95 100 100 25 81 68 – 88 100 46 0 58 45 – 65 94 5 44 30 – 55 42 0 19 8 – 30 10 5 5 – 15 2 1 0 – 5 45% 31.html 25 + 10 40 + 1031.50 mm 19.engineeringcivil.50 mm Crushed aggregate Table. 2: Approximate freewater content (kg/m3) required to give various levels of workability for nonairentrained (with normal entrapped air) concrete.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 Table.5 160 170 9/11 . the free water content is estimated by the expression.html 10/11 . Kaushal Kishore for submitting the revised mix design as per http://www.engineeringcivil.com are thankful to Er. We at engineeringcivil. 2/3Wf+1/3Wc Where.3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 Crushed 190 200 Note: When coarse and fine aggregate of different types are used.com/mixdesignforconcreteroadsasperirc152011. Wfsub>= Free water content appropriate to type of fine Aggregate And Wc= Free water content appropriate to type of coarse aggregate. com/mixdesignforconcreteroadsasperirc152011. http://www.html 11/11 .3/22/2016 Mix Design For Concrete Roads As Per IRC:152011 IRC:152011.engineeringcivil. This will be of great help to all civil engineering students and faculty who are seeking information on mix design based on revised IRC.
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