summary of is 15658

1. Precast concrete blocks
(IS 15658)
Jai prakash
Neeraj

2. Spcification
• Paver block
Aspect ratio < 4
• Aggregate
So3 < .5%
Water absorption < 2%
Nominal maximum size = 12 mm
• Pigment
Pigment quantity <9% by weight of cement concrete
Particles Should be finer than cement
• Durability
Dimension and tolerance :- Table 2
thickness and wearing layer :- Table 2
Compressive strength for individual paver block > 85% of specified strength (table 3)

3. Grade designation of paver blocks
Zero slump concrete
used.
Design according to
different traffic load as
per table1.
Quality of paver block
depends on
w/c,vibration,cement
grade,aggregate
quality,curing etc .

4. Precaution
Pigment shall not
contain zinc compound
.
Lead pigment shall not
be used .
Check visual defects
carefully .
The compressive
strength of two layer
block should meet the
specified requirement .

5. Requirements
Compressive strength requirement of paver block as per
table 3
For water absorption ,the mean value of 3 sample shall
not be more than 6% by mass of samples.
Sample requirement is given in table 4.

6. Tests for concrete block
Aspect ratio
Water
absorption
Compressive
strength
Abration
resistance
Tensile
splitting
strength
Flexural
strength
Freezing thaw
durability

7. Aspect ratio
Aspect ratio = mean length/mean depth

8. Water absorption
W(%) = (ww-wd)/wd
Ww = wet of block
removed after 24
hours immerging in
water
Wd = wet of specimen
after drying it in
ventilised oven at 107
degree for 24 hours

9. Compressive strength
C.S. = maximum load /
plan area
C.S. = apperent
compressive strength
of individual block.
Corrected compressive
strength is calculated
by multiplying c.s. to
correction factor given
in table

10. Abration resistance
•test is done on abration testing machine. It can be
done on dry as well as wet surface.
•calculate the density of wearing surface (PR).
•Disc speed should be 30rpm.
•dv is measure of abration resistance .

11. Table :- 1

12. Table : - 2

13. Table : - 3

14. Table 4