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1. For My Non Muslim Students :
"Feeling gratitude and not expressing it is like wrapping a present and
not giving it.“ ~ William Ward

2. For My Muslim Students:
"Therefore remember Me, I will remember you, And be thankful to Me,
and do not be ungrateful to Me." [The Noble Qur'aan [2:152]]

3. Lightweight aggregate concrete

4. Introduction
 Concrete made with lightweight aggregate.
 This concrete has good bond between
aggregate & the surrounding hydrated cement
paste.
 No serious adverse effects on durability when
lightweight aggregate is used.

5.  This concrete has low permeability and it
sound absorption rate can be rated as good.
 The low thermal conductivity of lightweight
aggregate concrete reduces the temperature
rise of the embedded steel in the case of fire.

6. Lightweight Aggregate
 There are 2 types of lightweight aggregate :
a) Natural aggregates
- pumice, scoria, tuff & cinders from
volcanic area
- used to produce lightweight insulating
concrete 250 – 1450 kg/m3.

7. b) Manufactured aggregates
- expanded clay, shale & slate are produced
from natural materials
- fly ash & slag are the main industrial waste
used to produce lightweight aggregate
- vermiculite and perlite manufactured from
natural materials can be used to produce
low – density concrete
- Only aggregates produced by expansion of
clay, shale, slate, fly ash or blast furnace
slag can be used to make structural
lightweight concrete 1350 – 1850 kg/m3.

8. Pumice (Natural aggregate)

9. Scoria (Natural aggregate)

10. Clinker aggregate or cinders

11. Vermiculite

13.  Requirement in lightweight aggregate are
given in ASTM C330 – 89 and BS 3797 : 1990
 Lightweight aggregates have an important
feature which is absent in normal weight
concrete.
 This feature is the ability of the lightweight
aggregate to absorb large quantities of water
and also to allow a limited ingress of fresh
cement paste into the open surface pores of the
aggregate particles, especially the larger ones.

14. Advantages
 Reduction in dead loads making savings in
foundations and reinforcement.
 Improved thermal properties.
 Improved fire resistance.
 Savings in transporting and handling precast
units on site.
 Reduction in formwork and propping

15. Design Mix
 The water demand of this concrete is strongly
affected by the surface texture and shape of the
aggregate particles.
 Since lightweight aggregate are very porous,
absorb mixing water and may continue absorb
water for several weeks after construction,
therefore the aggregates needs to be wet before
adding it into the mix.

16.  Partial replacement of lightweight fine
aggregate by normal weight concrete makes
placing and compaction of concrete easier.
 To improve workability and prevent
segregation, it may often by necessary to limit
the maximum slump or limit the water content
and the use of air entrainment.
 Excessive mixing should be avoided in
lightweight concrete manufacture because it
tends to break up aggregate particles

17.  Superplasticizers can be used with lightweight
aggregate concrete, but usually it is included in
the mix only when concrete is to be pumped.

18. Application
 Mainly used in non-load bearing walls in
domestic buildings and in in-filling panels in
framed structures.
 Can be used for structural application or for
insulation purpose depending on the types of
lightweight aggregate added in the mix.

19. Structure constructed using lightweight aggregate concrete

20. Structure constructed using lightweight aggregate concrete

21. IS IT TRUE???