– Mineral Admixture– Ordinary Portland Cement (P.O)– Portland granulated Blast-furnance-slag Cemen

t (P.S)– Portland-Pozzlana Cement (P.P)– Portland fly-ash cement (P.F)– Composite Portland Cement (P.C)

Chapter 3 Cement

§§3.3 Portland Cement With Mineral 3.3 Portland Cement With Mineral MaterialsMaterials

• It refers to the cement which is formed by Cement clinker, granulated blast-furnance slag and a little gypsum

• Quantities of granulated blast-furnance slag is 20% ～ 70%

HydraulicHydraulic cementing materialcementing materialClinkerClinker

granulated blast-furnance slag

GypsumGypsum

GrindingGrinding

P.SP.S

What is Portland granulated blast-furnance slag Cement

Technical Properties• Its property is different from Portland cement and

ordinary cement• Reasons: In cement, Portland cement and

ordinary cement is more and the clinker is little• Technical performance: It can be divided into 6

types:32.5, 32.5R, 42.5, 42.5R, 52.5, 52. 5R• Its early hardening is low• Other technical requirements are the same with

Portland cement

Tab.3.3.2 Strength Demands of P.S,P.P,P.F

Strength grade

Compression strength (MPa)

Fracture strength（MPa）

3d 28d 3d 28d

32.532.5R42.5

42.5R52.5

52.5R

10.015.015.019.021.023.0

32.532.542.542.552.552.5

2.53.53.54.04.04.5

5.55.56.56.57.07.0

Characteristics of P.S

• Strength is low in the early days and high in the later days– The hydration of slag cement takes 2 steps:– hydration of cement clinker; secondary hydration

reaction.– In the early days of a secondary hydration, the strength

is low with low speed and little hydration. But it is contrary to the later days.

– It is applicable to the prefabricated member cured in the middle days and projects with bearing slowly.

– But it is not applicable to the projects with the requirement for higher early hardening.

Comparing to Portland Cement and Ordinary Comparing to Portland Cement and Ordinary CementCement

• Strong anti-corrosion and poor carbonation resistance – It is applicable to the water concrete and

marine concrete – Not used in house with high concentration of

CO2 – Because of the low content of calcium

hydroxide.• Low hydration heat

– It is applicable to the project with mass concrete

Characteristics of P.S

• Temperature sensitivity

– It is applicable to the high temperature cuing because of temperature sensitivity.

• Low anti-freezing

– The early hardening is low .

– Water requirement of volcanic ash is big.Heat resistance

– It is applicable to the project with requirement of heat resistance concrete.

Characteristics of P.S

Poor permeability The large quality of mixing materials result in sharp arris of blast-furance slag and low water requirement and retentivity; therefore it can form bleeding channels easily.

Note: the latter 2 items are the features of P.S. and other properties same with PP 、PF cement.

Characteristics of P.S