Progress

HPCE_0_Intro

HPCE_1_Cement Chemistry

HPCE_2_Admixture, Aggregate, Water

HPCE_3_Fresh and Hardened Properties

HPCE_4_Durability

HPCE_5_UHPC

HPCE_6_Time Dependent Behavior

Calcium-silicate-hydrates

Let’s search in google scholar

(Metha and Monteiro 2006)

Calcium-silicate-hydrates

Most recent model:

Then, is it over?

(Shi 2008)

Can we solve below complicate problem?

Pore structure hierarchy (Metha and Monteiro 2006)

Intermixed pore network (Metha and Monteiro 2006)

Intermixed solid network (Metha and Monteiro 2006)

Type of Portland Cement (ASTM)

• Type I – ordinary Portland cement (OPC)

• Most commonly used in construction

• Type II – Modified cement

• Moderate sulphate resistance

• Moderate heat of hydration

• Type III – Rapid hardening Portland cement (RHPC)

• Used for obtaining high early strength, cold weather concreting, precast

concrete

• Type IV – Low heat Portland cement (LHPC)

• Used for mass concrete, hot weather concreting

• Type V – Sulphate resisting Portland cement (SRPC)

• Used in situation where ground water or soil have high sulphate contents

Types of Portland Cement (ASTM) in different countries

(M. Cardarone 2009)

Types of Portland Cement (ASTM) in different countries

(M. Cardarone 2009)Comparison between ASTM and BS-EN

Type of Portland Cement (ASTM)

Typical chemical composition and properties of Portland cements, ASTM Types I to V

ASTM C 109 50 mm mortar cubes.

I II III IV V

C3SC2SC3AC4AFC$H2Fineness (Blaine, m2/kg)Compressive strength [1day, MPa]Heat of hydration (7 days, J/g)

55181086

36515350

55196115

37514265

55171086

55024370

42324154

3404

235

55224124

38012310

Strength of concrete made with different cements

C

Rate of heat evolution measured as temperature rise of mass concrete stored under adiabatic conditions

Role of gypsum in cement hydration

(M. Cardarone 2009)

Illustration of an “under-sulfated” paste. When under-sulfated during the early stages of hydration, flash set can occur.

Illustration of an ideally balanced paste during the early stages of cement hydration. The system is being supplied sulfate at the same time it is needed to control C3A reactivity.

Illustration of an “over-sulfated” paste. When over-sulfated during the early stages of hydration, false set may occur.

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)

Role of gypsum in cement hydration

(Metha and Monteiro 2006)