1. 4.7.3 High Performance Concrete (HPC)
Introduction
Characteristics
Techniques
Proportion ratio
Properties
Application

2. Introduction
HPC refers to excellent materials made by strict construction craftworks, It is convenient to cast and compact with no segregate It is steady in volume and mechanical property.
ACI international conference first proposed that high performance concrete can’t be made by regular materials and technology to meet synthetic properties and uniformity in 1990.
It has good performance in toughness, durability.
It can be applied to high architectures, bridges and those exposed in harsh environment.

3. Characteristics
HPC is a new kind of concrete with great feasibility, high strength and durability.
Its characteristics are as follows:
The concrete mixture has good performance in mobility, self-impact and can ensure uniformity and impact with slight vibration or without vibration.
The concrete mixture shows good cohesion, water retentivity, plasticity, stability and pump ability with no segregate in water.
It can be used in mass concrete casting because low hydration heat is produced in the process of setting and hardening.
It can keep volume steady and have small shrinkage deformation after hardening, so there are few defaults such as micro cracks inside concrete and it forms a stable structure.

4. Characteristics Its characteristics are as follows:
It has good protective ability of reinforced bars in concrete in high solidity and strong resistance of permeability of water, corrosive liquid and chlorineion.
It contains little Ca(OH)2 and hydrated calcium sulfate, which are easy to be eroded by sulfate and magnesium to ensure the resistance to seawater corrosion.
Concrete has excellent permeability and proper content of gas with even and impact bubbles so it has good performance in freeze-thaw resistance and fastness to efflorescence. It is easy to be cast for the concrete structure in the area which can be touched by waves.
It can be used in prefabricated concrete for its high strength and lower content of binding material, which is less than that in ordinary concrete.

5. Techniques
Selection
Cement with medium heat, MDF, DSP; super fine mineral admixture; superplasticizer; Dmax<15mm.
Parameter
W/ C<0.4, W<175; Sp=36-42%; binding material=
Craft works control
Forced mixing, high frequent vibration; pumping up, SL>200; protection in early days

6. Tab.4.7.2 Proportion Ratio items C30 Ordinary concrete C50 Pumped
C60 Pumped concrete
C70
Pumped concrete
amount of cement（Kg/cm3）
460
357
400
amount of fly-ash in Grade 1（Kg/cm3） / 63 70
NSF-A silicon
50~63
76~88
103~112
Cement + fly-ash + NSF-A silicon
474
502
578
amount of water(Kg/cm3)
200
114~118
98~102
slump（cm）
20±2
content of gas（％）
2.6
2.4
2.1
compressive strength after
28 days（MPa） 39 58 69 79

7. Properties Comparison of Properties (Tab.4.7.3)
Dry Shrinkage (Tab.4.7.4)
Time and the Slump Loss (Tab.4.7.5)

8. Tab.4.7.3 Comparison of Properties
C30OPC
C50HPC
C60HPC
compressive strength(MPa) 39 58 69
bending strength(MPa)
5.1 7
5.4
axial tensile strength(MPa)
3.1
4.7
5.2
compressive elastic modulus(GPa)
27.8
34.3
35.9
Loss ratio of resistance to impact(%)
7.1
3.2
2.5

9. Tab.4.7.4 Dry Shrinkage kinds of concrete shrinkage ratio(×10-6) 2d 7d
109
200
286
431
577
621
C50
172
239
345
433
475
C60 55
622
163
124
121
442
C70 96
170
232
326
430
466

10. Tab.4.7.5 Time and the Slump Loss
C50
C60
C70
beginning 23
20.7
21.4
1 hour
20.5 17
2 hours
20.4 20 15
2.5 hours
19.8 14

11. Application In foreign countries:
German concrete structure design has reached to C110
In Norway C105, HPC in 85～90 is widely used in road construction
Denmark Belt-connection between tunnels and bridges
Designed for 100 years
Applied in tower structure, prefabricated beam and block
Japan
Super strength and high performance concrete for apartment buildings
Super durable concrete over 500 years has been developed

12. Application In China： Shanghai Jin Mao Tower C60
Beijing West Railway Station C60
Beijing Jing’an Center C80
Liaoning Goods and Material Mansion C80
Nanjing Posts and Telecommunications Center C60
Changchun International C55
Guangzhou Humen Bridge C50
Shanghai Yangpu Bridge C50
Steel concrete for Changjiang River Bridge Wanxian County C60