This document discusses a study on the impact of fine content variation in manufactured sand (M-sand) for G35-A concrete performance used in water retaining structures. The objectives are to identify current problems with using M-sand, examine property variations of M-sand in Colombo, study how fine content impacts G35-A concrete, and develop guidelines for optimum M-sand replacement. Testing showed compressive strength decreases with higher fine content. A 30% M-sand replacement produced the best results for G35-A concrete. Up to 15% fine content yielded satisfactory results for 70% replacement if cured for only 1 hour. Further study of clay content variation and particle shape is recommended.

1. THE IMPACT OF FINE CONTENT
VARIATION IN M-SAND FOR G35-A
CONCRETE PERFORMANCE USED
IN WATER RETAINING STRUCTURE
SUPERVISED BY
DR M. S. T. PRIYADARSHANA
ENG. MADDUMA B. THENNAKOON
PRESENT BY
K. K. A. N. PRASANGIKA 313344292
M. P. C. GIMHAN 613344291
K. D. V. SOLAMAN 413277746

4. • The minimum cement content - 325 kg/m3
• For reinforced concrete
• The maximum 400 kg/ m3 of ordinary
Portland cement
A maximum water/cement ratio - 0.55
The 28-day strength ≥ 35 N/𝒎𝒎𝟐

6.  Fine content is significantly high in m-sand.
 Water demand is high.
 Clay content variation is high.
 M sand has angular shape particles

8. AIM
• Study the impact of fine content variation in M-sand for
the G35A concrete performance and preparation a
guideline to obtain the optimum replacement of M-sand.
OBJECTIVES
• Surveying to identify the current problems in water
retaining structures with the usage of M-sand
• To identify the variation of properties of M-sand around
the Colombo area
• To study the impact of fine content variation in M-sand
for G35A concrete performances.
• To prepare a guideline to obtain the optimum
replacement of M-sand for G-35A concrete by analyzing
the fine content variation.

10. 35
36
37
38
39
40
41
42
43
0 20 40 60 80 100
38.07
39.38 39.53
42.87
40.69
39.82
compressive
strength
MPa
Percetage replacement of natural sand by M sand
Variation in compressive strength of concrete Mpa
Priyanka and Dilip(2012)

11. (Halesh et al. 2017)

12. Yalley and Sam(2018)

13. 0
5
10
15
20
1% 3% 5% 7% 10%
Compressive
strength
losses
Clay content in aggregates
Variation of compressive strength losses
3 days
7 days
14 days
28 days
Twubahimana and Mbereyaho(2013)

14. Control sample 100% River sand

15. CEMENT - 390 kg
WATER - 176 L
FINE AGGREGATES (45%) - 880kg
W/C RATIO - 0.45
COARSE AGGREGATES(55%)- 1075 kg
ADMIXTURE(SIKA_PLAST 2055)- 4.290 L

17. Daduru Oya Water Supply
Project
Ambathale Water
Treatment Project
Anamaduwa Water
Treatment Project
Matara Water Treatment
Project

28. 0
10
20
30
40
50
60
70
80
90
100
110
0.01 0.1 1 10
Percentage
Passing
(%)
Particle size (mm)
River sand
MS1
MS2
MS3
MS4
MS5
BS 882 upper limit
BS 882 lower limit
PARTICLE SIZE DISTRIBUTING CURVES

35. • There is a significant Variation in Properties of locally available M sand.
Specially in the fine content.
• Fresh state properties of G35A concrete has decreased with the
increasing of fine content.
• 30% of replacement in M sand has shown the best properties for G35A
concrete.
• When 70% of partial replacement is used for G35A concrete then up to
15% of fine content has given satisfactory results but only for 1hr
retention time.
• Compressive strength was generally decreased with the increasing of
fine content.

36. • Study the clay content variation and impact of shape of M-sand to
the G35A concrete performance to improve the guide line
provided.
• The impact of variation in properties of M-sand to the concrete
shrinkage can be studied, as concrete shrinkage also a major issue
when dealing with M-sand.