MIX DESIGN OF DLC (DRY LEAN CONCRETE)

Reference Specification Code :

• MORTH 5th Rev.
• IRC-15 
• IRC SP-49
• IS-2386

STEP-1

Test all the individual materials sample like Coarse Aggregate(20mm , 10mm ) & Fine Aggregate (Stone Dust , River Sand ) as per MORTH or other DLC specified IS Sieve 

• Individual Grading of 20 mm Coarse Aggregate        

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• Individual Grading of 10 mm Coarse Aggregate 

• Individual Grading of Stone Dust  

STEP-2

After Grading of Individual aggregate you should blending all individual items in suitable proportion and tri to result will be near to mid value of upper and lower limit as specified in code. 

• Blending All in Aggregates

BLENDING FOR DRY LEAN CONCRETE (DLC)
Ratio of Blending (%)				20 MM	10 MM	Sand	Stone Dust	Total
				30%	35%	0%	35%	100%
Sieve size (mm)	Avg. % of Passing				% of Passing	Acceptable Limit As per MORT&H		Mid-Value
	20 MM	10 MM	Sand	Stone Dust		Lower Limit	Upper Limit
26.5	100.00	100.00		100.00	100.00	100	100	100.0
19	62.16	100.00		100.00	88.65	75	95	85.0
9.5	4.16	73.12		100.00	61.84	50	70	60.0
4.75	0.13	4.83		96.89	35.64	30	55	42.5
2.36	0.00	1.08		86.50	30.65	17	42	29.5
0.600	0.00	0.00		48.77	17.07	8	22	15.0
0.300	0.00	0.00		33.24	11.63	7	17	12.0
0.150	0.00	0.00		26.86	9.40	2	12	7.0
0.075	0.00	0.00		15.09	5.28	0	10	5.0

STEP-3

After getting the aggregates blending ratio, We will check it practically by mixing all Coarse and Fine aggregate as per Blending proportion and then test the Gradation 

Practical Gradation			Wt. of Initial Sample (gm)=			10000
Sieve Size	Weight Retained	% Weight Retained	Cumulative % Retained	Cumulative Passing	Acceptable Limit As per MORT&H
(mm)	(gm)	(%)	(%)	(%)	Lower Limit	Upper Limit
26.5	0	0.00	0.00	100.00	100	100
19	988	9.88	9.88	90.12	75	95
9.5	2980	29.80	39.68	60.32	50	70
4.75	2152	21.52	61.20	38.80	30	55
2.36	520	5.20	66.40	33.60	17	42
0.6	1361	13.61	80.01	19.99	8	22
0.3	1079	10.79	90.80	9.20	7	17
0.15	185	1.85	92.65	7.35	2	12
0.075	298	2.98	95.63	4.37	0	10

STEP-4

If we found the practical grading is within specified limit then we check other properties like Combined Flakiness Index & Elongation Index , Aggregate Impact Value (AIV) , Water Absorption & Sp. Gravity etc. as Specified in Code or MORTH

STEP-5

Find out the Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) by Modified Proctor Test as per IS 2720 P-8

MDD= 2.516 gm/cc & OMC= 5.5 %

STEP-6

Trial Mix Data Sheet- DLC (Dry Lean Concrete)

STEP-7

After Trial, Check the 3 days and 7 days Cube Strength , As per MORTH 5th Rev. Required 7 days strength is 10 N/mm2