CCS355 Neural Network & Deep Learning UNIT III notes and Question bank .pdf
Self compaction concrete
1.
2. ABSTRACT
Self compacting concrete (SCC) is a development of
conventional concrete, in which the use of vibrator for
compaction is no more required. Self-compacting
concrete was first developed in 1988 to achieve durable
concrete structures.
Several studies in the past have revealed the usefulness
of fibers to improve the structural properties of
concrete like ductility, post crack resistance, energy
absorption capacity etc
4. INTRODUCTION
Concrete is the most versatile construction material
because it can be designed to withstand the harshest
environments while taking on the most inspirational
forms. Engineers are continually pushing the limits to
improve its performance with the help of
innovative chemical admixtures and
supplementary cementitious materials.
5. INTRODUCTION
Concrete that requires little vibration or compaction
has been used in Europe since the early 1970s but self-
compacting concrete was not developed until the late
1980's in Japan. In Europe it was probably first used in
civil works for transportation networks in Sweden in
the midl990's. The multi-national, industry lead
project "SCC" 1997-2000 and since then SCC has
found increasing use in all European countries.
6. OBJECTIVE
To identify the three key properties of SCC i.e. filling
ability, passing ability and segregation resistance
To determine the workability of SCC using Slump
Cone Test, U Tube Test, L Box Test and V Funnel Test.
To study the Structural strength of SCC while alkaline
attacks on it
To study the Strength and behavior of using Fly ash to
the SCC.
7. SCOPE
To improve filling capacity through highly
congested reinforcement by using the Self Compacting
concrete.
To reduce the construction time in the project.
8. SPECIFICATIONS
Generally a good quality of cement like 53 grade
cement is preferred
The maximum size of the aggregates depends on the
particular application and is usually limited to 12 mm.
Fly ash is a fine inorganic material with pozzolanic
properties, which can be added to SCC to improve its
properties and also as a substitute of cement to certain
extent.
9. ADVANTAGES
Faster construction.
Reduction in site man power.
Better surface finishes.
Easier placing.
Reduced noise levels in work site.
Safer working environment.
Economical construction.
Time of construction is minimized.
10. APPLICATIONS
SCC may be used in pre-cast applications or for
concrete placed on site. It can be manufactured in a
site batching plant or in a ready mix concrete plant and
delivered to site by truck.
Due to the flowing characteristics of SCC it may be
difficult to cast to a fall unless contained in a form.
12. CHARACTERISTICS OF HARDENED SCC
In normal concrete, during vibration, water tends to
migrate to the surface of the coarser particles causing
porous and weak interfacial zones to develop.
In case of well-designed SCC the homogeneity,
mobility,
Cohesiveness helps placing concrete in formwork
without compaction. This helps in better interface
between coarse aggregate and mortar paste as minimal
interfacial zone develops.
13. ALKALINE RESISTANCE ON SCC
The cubes of size 150mm x 150mm x 150mm were casted
and cured for 28 days.
The specimens were taken out from the curing tank and
initial weight (W1) of the specimen was observed and
noted.
Three percent of sodium hydroxide (NaOH) was added
with the water and solution was prepared. The concrete
specimens were immersed in the solution for over a period
of 90 days.
After 90 days of immersion The surfaces were cleaned well.
The concrete specimens were weighed(W2) and then
tested in the compression testing machine.
14. LITERATURE REVIEW
M.C. Alonso et al (2008) mentioned that Self-Compacting
Concrete reinforced with polymeric fibers
(Polypropylene fibers, PPF) has been considered in
present work. First, the mechanical and micro structural
characterization has been determined. Further the
influence of the presence of the PPF in the SCC durability
properties of the material has been studied at Laboratory,
using different indicators. Finally, the response of both
types of material with respect to resistance at high
temperature was evaluated through microstructure
analyses and mechanical properties changes suffered for
the material.
15. LITERATURE REVIEW
Zoran Grdic et al (2008) mentioned that
Self−compacting concrete is one of "the most
revolutionar developments" in concrete research;
this concrete is able to flow and to fill the most
restacted places of the form work without vibration.
There are several methods for testing its properties in
the fresh state: the most frequently used are
slum−flow test, L−box and V−funnel. This work
presents properties of self−compacting concrete,
mixed with different types additives: fly ash, silica
fume, hydraulic lime and a mixture of fly ash and
hydraulic lime.