DESIGN OF HIGH PERFORMANCE CONCRETE (HPC) MIXTURE IN AGRESSIGE ENVIRONMENT

Prepared by:
Saeed Khamis Al Haddadi Nayel Rashid Al Shamsi Mansour Mohd Al Shebli Saeed Nahyan Al Ameri Muath Mohd Al Mazrooei 200203853 200216968 200204979 200204458 200205340

United Arab Emirates University College of Engineering Civil and Environmental Engineering Department Graduation Project II

Advisers name:
Dr. Amr S. El Dieb
2st Semester 2007/2008

Introduction Objective Mix Design Methods Experiment and Testing Gant Chart

HPC is defined as concrete which meets special performance and uniformity requirements that cannot always be achieved by using only the conventional materials Concrete is composed principally of aggregates, Portland cements, water, and may contain other cementations materials and/or chemical admixtures.

The selection of concrete proportions involves a balance between economy and requirements for place ability, strength, durability, and density (i.e. its performance). HPC is characterized by its high performance in any of its properties or characteristics Usually the term HPC is used to define high durable concrete (i.e. concrete characterized by high durability)

The required durability characteristics are governed by the application of concrete and by conditions expected to be encountered at the time of placement. These characteristics should be listed in the job specifications.
Environment
Impact

Concrete
Impact Resistance Durable Concrete (HPC)

Deterioration

Environment

Concrete

Objective
The effect of different SCM with various dosages on HPC mixes will be evaluated for various aggressive environments. Different concrete mix design methods will be implemented and compared to design HPC mixes. Control concrete mix will be designed having a compressive strength of 40 to 50 MPa, slump between 100 120 mm and the cement content is 350 kg/m3.

Mix Design Methods

There are two well known mix design methods implemented by various codes : BS 8328 mix design method. ACI 211.1-91 mix design method.

To perform a concrete mix design several criteria (i.e inputs) are needed together with the properties of the used materials The criteria needed includes: Required strength Required slump Minimum cement content Properties of available or used materials; investigated in GPI

BS Method
Approximate compressive strength (N/mm2) of concrete mixes made with a free water/cement ratio 0.5

BS Method..
Relationship between compressive strength and free water-/cement ratio
47

From this graph w/c ratio is determined for the required strength

0.47

BS Method
Approximate free water content (Kg/m3) required to give various levels of workability.

Slump is adjusted by admixture dosage

BS Method

Estimated wet density of fully compacted concrete to calculate the aggregate quantity
2420

170

BS Method
Determines the mixing ratio of fine and coarse aggregates depending on the grading zone of the fine aggregate (1,2,3 &4)

BS Method

35%

ACI Method
Relationship between water-cement or water- cementations materials ratio and compressive strength of concrete

ACI Method
Approximate mixing water and air content requirements for different slumps and nominal maximum sizes of aggregates

ACI Method
Volume of coarse aggregate per unit of volume of concrete

Discussion
After we used two methods we found ACI method is not appropriate to design our control mix because the maximum strength we can design using this method is 34 MPa and it is using cylinder not cube so BS method is used.

Also there isnt any mix design method which considers the incorporation of supplementary materials such as Slag and Silica fume. Typical concrete mix used in the country is designed using material investigated in GPI.

Criteria for mix design

Parameters: Silica fume Slag Combination of silica fume and slag Many ready mix company in my country used silica fume in range of 8% and slag in range of 40% to 60% of cement content. We will use 5% , 8%, and 15% of silica fume to make comparison between it. Also we will used 25%,40% and 60% of slag to compare between it. In addition, we will study the ternary blends ( silica fume and slag ).

Criteria for mix design

Strength 40-50 MPa Slump 100- 120 mm controlled by admixture C.C. at least 350 kg/m3 Mix Proportions/ m3
Dune Cement Sand sand 350 555 186 C.Agg.(S220mm) 790 C.Agg.(S110mm) 333 Water cement ratio Water Slag 0.47 166 0 Silica Fume 0 Admixtures Variable

Batch Quantities
Cement Sand 22.4 35.5
Dune sand 11.9 C.Agg.(S220mm) C.Agg.(S1-10mm) Water Slag 50.5 21.3 10.6 0 Silica Fume 0

Admixtures Variable

EXPERMINT AND TESTING

Introduction
SCM

SCM usually works in two ways: As microfilling materials i.e. physical effect (in early stages) Pozzolanic materials (in late stages)

Microfilling Effect (Physical effect)

Introduction
Pozzolanic Reaction

SCM in finely divided form provides a source of reactive silica that in the presence of moisture will combine with CH to form C-S-H and other cementing. Typically slow down hydration, but significantly improve durability and long-term strength

Introduction
Pozzolanic Reaction
2C3S + 6H C-S-H + 3CH 2C2S + 4H C-S-H + CH CH + SCM + H C-S-H

Introduction
Hydration of C3S & C2S

CH

C-S-H

SCM Material
Silica Fume

Result of the reduction of high-purity quartz with coal in an electric arc furnace in the manufacture of silicon or ferrosilicon alloy.
Have large surface area

SCM Material
Slag

Made from iron blast-furnace slag. It is a non-metallic hydraulic cement consisting essentially of silicates and alumino-silicates of calcium.

Mixes
Batch Quantities
Total Quantities C1 Cement Sand Dune Sand kg kg kg 22.4 35.5 11.9 50.5 21.3 10.6 0.0 0.0 C1-SF5 C1-SF8 C1-SF15 C1-S25 21.3 35.4 11.8 50.4 21.2 10.6 0.0 1.1 20.6 35.3 11.8 50.3 21.2 10.6 0.0 1.8 19.0 35.1 11.8 50.0 21.1 10.6 0.0 3.4 16.8 35.4 11.8 50.4 21.2 10.6 5.6 0.0 C1-S40 13.4 35.3 11.8 50.2 21.2 10.6 9.0 0.0 C1-S60 C1-S25-SF5 C1-S25-SF8 C1-S40SF5 for all Mixes 9.0 35.2 11.8 50.1 21.1 10.6 13.4 0.0 15.7 35.3 11.8 50.3 21.2 10.6 5.6 1.1 15.0 35.3 11.8 50.3 21.2 10.6 5.6 1.8 12.3 35.3 11.8 50.2 21.1 10.6 9.0 1.1 166 353 118 503 212 106 48 10

C.Agg.(S2-20mm) kg C.Agg.(S1-10mm) kg Water Slag Silica Fume lit kg kg

Admixtures

kg

To be adjusted to maintain a constant slump of 100-120mm

Lab strategy

Batching Strategy

Table 4.2.1
Mix name C1 C1-S25- C1-S25- C1-S40C1-SF5 C1-SF8 C1-SF15 C1-S25 C1-S40 C1-S60 SF5 SF8 SF5 Th 6/3 Mo 10/3

Mix date Mon 18/2 Tu 19/2 Th 21/2 Mo 25/2 Tu 26/2 Th 28/2 Mo 3/3 Tu 4/3

Lab strategy
Testing Strategy
Table 4.2.2

Laboratory

Laboratory

Laboratory

Laboratory

Laboratory

Testing
We did four type of tests which are: Compressive Strength (Cube Test): Normal compressive strength Compressive Strength in Sulfate Solution

Tensile Strength.
Sorptivity Test. Resistivity Test

Normal compressive strength

Compressive Strength

10 cm

10 cm

Normal compressive strength

Figure 5.4: Compressive strength at 7, 28 and 56 days for different dosage of silica fume

Normal compressive strength

Figure 5.5: Compressive strength at 7, 28 and 56 days for mixes with different dosage of slag

Normal compressive strength

Figure 5.6: Compressive strength at 7, 28 and 56 days for mixes combination with slag and silica fume in different dosage.

Compressive strength in sulfate solution

100 Liter with 5% NaSO4

Water heater

Compressive strength in sulfate solution

Compressive strength in sulfate solution

Silica fume effect:

Table 5.3.1.1: Test results for different percentage of SF

Compressive strength in sulfate solution

Silica fume effect:

Figure 5.7: Effect of sulfate solution on cube strength in ambient temperature for mixes with different SF dosage

Compressive strength in sulfate solution

Silica fume effect:

Figure 5.8: Effect of high temperature sulfate solution on cube strength for mixes with different dosage of SF

Compressive strength in sulfate solution

Silica fume effect:
Table 5.3.1.2: Reduction in strength at different immersion periods for different percentages of Silica Fume

Compressive strength in sulfate solution

Silica fume effect:

Figure 5.9: Difference in strength between hot results and ambient for differ percentages of SF in sulfate solution

Compressive strength in sulfate solution

Slag effect: Table 5.3.2.1: Test results for different percentage of Slag

Compressive strength in sulfate solution

Slag effect:

Figure 5.10: Effect of ambient temperature sulfate exposure on mixes with different Slag contents

Compressive strength in sulfate solution

Slag effect:

Figure 5.11: Effect of high temperature sulfate exposure on mixes with different Slag contents

Compressive strength in sulfate solution

Slag effect:

Compressive strength in sulfate solution

Slag effect:

Figure 5.12: Difference in strength between hot results and ambient for differ percentages of Slag in sulfate solution

Compressive strength in sulfate solution

Combined slag & silica fume:

Table 5.3.3.1: Test results for different percentage of Slag and Silica Fume

Compressive strength in sulfate solution

Combined slag & silica fume:

Figure 5.13: Effect of high temperature sulfate exposure on mixes with combined slag and silica fume with different contents

Compressive strength in sulfate solution

Combined slag & silica fume:

Figure 5.14: Effect of ambient temperature sulfate exposure on mixes with different Slag and Silica Fume contents

Compressive strength in sulfate solution

Combined slag & silica fume:

Table 5.3.3.2: Reduction in compressive strength for combined slag and silica fume mixes in sulfate solution.

Compressive strength in sulfate solution

Combined slag & silica fume:

Figure 5.15: Difference in strength between hot results and ambient for differ percentages of Slag and Silica Fume in sulfate solution

Compressive strength in sulfate solution

Strength Reduction:

Table 5.3.4.1: Reduction in compressive strength for combined slag and silica fume mixes in sulfate solution

Compressive strength in sulfate solution

Strength Reduction:

Figure 16: Strength reduction at 56 age

Tensile strength
Splitting tensile Strength

10 cm

20 cm 2*Failure Load (N) *200*100

Ft =

Tensile strength

Table 5.4.1: Test results at 7 & 28 days of age

Tensile strength
Split Strength in Difference Ages in Slica Fume
5.00 4.50 4.00
Tensile Strength (Mpa)

3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00 C1 C1-SF5 C1-SF8 C1-SF15 Mixes Name 7 Days 28 Days

Figure 5.18: Splitting tensile strength for silica fume mixes.

Tensile strength

Figure 5.19: Splitting tensile strength for slag mixes.

Tensile strength

Figure 5.20: Splitting tensile strength for combine slag & silica fume mixes.

Sorptivity test
ASTM C 1585; Sorptivity Test
This test is based on the Halls theory and adopted in ASTM recently Require a concrete disc of at least 300gm weight Concrete specimens are oven dried The specimens sides are sealed using any sealant One surface of the specimen is exposed to water and the change in weight with time is measured (at least 5 measurements) over 30 minutes period Plot the graph between penetration depth (i) and square root of time (time1/2) to calculate Sorptivity

Sorptivity test
Surface sealant (electrical vinyl tape)

Container

Water Concrete Specimen

Circular support

Sorptivity test

Sorptivity test
One dimensional flow through partially saturated concrete can be expressed using Halls expression
Constant Exposure time (min)

i A S t
Penetration depth (mm)
Rate of Absorption i.e. Sorptivity (mm/min1/2)

Sorptivity test
Change in specimen weight (gm)

W i A
Water density (gm/mm3)

Cross sectional area (mm2)

i
Slope = Sorptivity (S) mm/min1/2

Constant = A

Time1/2

Sorptivity test
Specimen Location and Code = C1-1 Specimen Diameter (mm) = 100 mm

Sorptivity test
Table 5.1.1: Average Sorptivity test value at 28 and 56 days of age

Sorptivity test
Figure 5.1: Comparison of Sorptivity values between control mix and different dosage of silica fume.

Sorptivity test

Figure 5.2: Comparison of Sorptivity values between control mix and different dosage of Slag.

Sorptivity test

Figure 5.3: Comparison of Sorptivity values between control mix and different dosage of Slag and silica fume.

Resistivity test
This test is based on the electrical conductivity of concrete. electrolytic process that takes place by the movements of ions in the cement matrix. This ionic movement will take place when contaminants such as chloride ions or carbon dioxide are introduced into the cement mortar matrix. A highly permeable concrete will have a high conductivity and low electrical resistance.

Resistivity test

Resistivity test
The concrete resistivity was considered to be a measure on how the concrete would protect the steel reinforcement against corrosion.

Table 5.5.1: Resistivity Limits

Resistivity test

Resistivity test

Resistivity test

Conclusion

Sulfate Environment

Slag Dosage

Conventional Mix

Sl ag

Si l ic a

Figure 6.1: Schematic diagram for selecting SCM (slag and silica fume) for different exposure conditions

Su C En o lfa vi rro te & ro si nm ve en t

Fu m e

Silica Fume Dosage

Corrosive Environment

Gant Chart