Click to edit Master title style2019 CFBA AGM

Advances in

Agricultural

Concrete

Click to edit Master title styleAgenda

➢ Overview of Ontario Concrete Industry

➢ Basics of Concrete

➢ Concrete Performance

➢ Sulphate Resistance

➢ Workability

➢ Sustainability

Click to edit Master title styleRMCAO Concrete Facts

➢ 160 Company Members (Active & Associate)

➢ 5 Association Staff Members

➢ Represents 95% Ontario’s concrete

▪ 270 Concrete Plants

▪ 3,500 Concrete Trucks

▪ 10.0 Million m3

➢ www.rmcao.org

Click to edit Master title styleBasics of Ready Mixed

Concrete Production

Click to edit Master title styleConcrete Standards and Codes

➢ Ontario Building Code (OBC)

▪ CSA A23.1/.2 – Concrete Materials and Methods of

Concrete Construction (2014)

▪ National Farm Building Code - 1995

➢ Ontario Provincial Standards & Specifications

▪ Municipal Version – 2019

▪ Provincial Version – 2019

Click to edit Master title styleWhat is Concrete?

➢ It is not the same thing as

CEMENT !

Click to edit Master title styleWhat is Concrete?

It is a man-made rock

➢ Moldable into an infinite number of shapes

▪ Serving both structural and aesthetic needs

▪ Combination of materials blended /mixed together with specific proportions

Canadian War Museum – OttawaMoriyama & Teshima Architects

Click to edit Master title styleWhat do we want from Concrete?

Performance has traditionally been measured by:

Compressive

Strength

• Great in Compression

• Weak in Tension (10%)

Click to edit Master title styleWhat do you want from Concrete?▪ Early strength

▪ Long term strength

▪ High workability

▪ Freeze-thaw resistance

▪ Chemical resistance

▪ Low permeability

▪ Long service life

▪ Fire resistance

▪ Small environmental footprint

Click to edit Master title styleWhat do you want from Concrete?

Standard Concrete Testing:

➢ Plastic Concrete Temperature

➢ Slump / Slump

➢ Plastic Air Content

➢ Compressive Strength

Advanced Concrete Testing:

➢ Chloride Ion Penetrability (RCP)

➢ Hardened Air Void System

➢ Linear Shrinkage

Click to edit Master title styleRaw Materials Used to

Make Concrete

Click to edit Master title styleRaw Material Fundamentals

Raw Materials in Concrete

• Portland Cements

• GU & GUL

• Slag

• Fly Ash

• Silica Fume

• Aggregates

• Fine

• Coarse

• Water

• Admixtures

Click to edit Master title stylePortland Cement Types

➢ GU – General Use

➢ GUL – General Use Limestone

➢ HE – High Early Strength Gain

➢ HS – High Sulfate Resistance

▪ HSb – Equivalent Performance with SCMs

Click to edit Master title styleSupplementary Cementing Materials

SCM’s

➢ Ground Granulated Blast Furnace Slag

(Iron Blast Furnace By-Products)

➢ Fly Ash

(Coal Burning By-Product)

➢ Silica Fume

(Silicon Blast Furnace By-Product)

Click to edit Master title styleRaw Material Fundamentals

Hydration Reactions

➢ Portland Cementing Reactions

PC + W C-S-H + CH

➢ Supplementary Cementing Reactions

SC + W + CH C-S-H

Click to edit Master title styleWhy does it Work ?

By improving the Hydration Products

Click to edit Master title styleChemical Admixtures for Concrete

Standard Chemical Admixtures as per ASTM C494:

Type Description

A Water-Reducing

B Retarding

C Accelerating

D Water-Reducing & Retarding

E Water-Reducing & Accelerating

F Water-Reducing, High Range

G Water-Reducing, High Range & Retarding

Click to edit Master title styleChemical Admixtures

Additional Concrete Admixtures:

➢ Air-Entraining

➢ Flowing Concrete / Superplastizer

Miscellaneous Admixtures:

➢ Corrosion Inhibiting

➢ Hydration Stabilization

➢ Shrinkage Reducing

➢ Colour

Click to edit Master title styleWater for Concrete Mixes

➢ Potable water

➢ Recycled washout water is acceptable (if tested)

Click to edit Master title styleCement Hydration

Click to edit Master title styleHydration Basics

➢ Cement hardening process:

▪ Chemical reaction with water called “hydration”

▪ Temperature and time dependent

➢ All chemical reactions produce heat

▪ Creates a rise in concrete temperature

▪ High internal temperatures

can lead to cracking

Click to edit Master title styleWater to Cementing Material Ratio

Total Water (kg)

Total Cementing Materials (kg)

W/CM affects:

➢ Compressive Strength

➢ Permeability

➢ Shrinkage & Cracking

➢ Abrasion Resistance

Click to edit Master title styleWater to Cementing Material Ratio

Click to edit Master title styleAir Entrainment for

Exterior Concrete

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Non-air-entrained

0oC

Saturation > 91.7%Mechanism of Frost Damage

Click to edit Master title styleMechanism of Frost Damage

Non-air-entrained

0oC

Saturation > 91.7%

- 5oC

Click to edit Master title styleMechanism of Frost Damage

Non-air-entrained

0oC

Saturation > 91.7%

- 5oC

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Non-Air-Entrained Concrete Air-Entrained Concrete

Click to edit Master title styleMechanism of Protection by Air Voids

Air-entrained

0oC

Saturation > 91.7%

- 5oC

Click to edit Master title styleMechanism of Protection by Air Voids

Air-entrained

0oC

Saturation > 91.7%

- 5oC

Click to edit Master title styleMechanism of Protection by Air Voids

Air-entrained

0oC

Saturation > 91.7%

- 5oC

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Air-entrained

0oC

Saturation > 91.7%

- 5oC

Mechanism of Protection by Air Voids

Click to edit Master title styleAir Void Before and After Ice Formation

D. Corr, 2001

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From Neville, 1995

Why is Air Entrainment Critical?

Click to edit Master title styleConcrete Requires 3 Things for Curing

1. Minimum Curing Period 72 hours to 7 Days

2. Minimum Curing Temperature of 10°C

3. Maintain the concrete at 100% Relative Humidity

Click to edit Master title styleWhat Happens When I Don’t Cure the Concrete?

Scaling

Freeze/Thaw

Chemical Attack

Mortar Flaking

Crazing

Dusting

Click to edit Master title styleWhat is the best mix for the project?

➢ Workability appropriate for the placement

method (if there are requests for water addition

then the mix needs to be changed!)

➢ Required strength at the requested time

➢ Durability for the intended use & service

life

➢ Mix is economical

Click to edit Master title styleMinimum Concrete

Requirements

Click to edit Master title styleDo We Really Care?

Complying with the Building Code is Always Nice!

Click to edit Master title styleCSA A23.1 Exposure Classes

Click to edit Master title styleA Exposure Classes

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Courtesy David Fowler, 2001

Hydrogen Sulphide Gas Attack (Sewer)

Click to edit Master title styleAgricultural Corrosion Conditions

Click to edit Master title styleOBC 2012 – Part 4

4.4.5.1. Liquid Manure Storage Tanks

1) Liquid manure storage tanks shall be constructed of steel, reinforced concrete or prestressed concrete.

2) Liquid manure storage tank walls, bases and appurtenances, including piping for the conveyance of liquid manure and associated connections and joints, shall be designed and constructed to prevent leakage of contents.

3) Concrete for liquid manure storage tanks shall,

a)be made from HS or HSb cement,

b)have a 28-day strength of at least 32 MPa, and

c)have a water/cement materials ratio of not more than 0.45.

Click to edit Master title styleOBC 2012 – Part 4

Concrete Issues:

➢ HS Cement is not available in Ontario

➢ HSb is typically produced using slag replacement

➢ Exact slag replacement will vary between 25 – 50%

Click to edit Master title styleReducing Concrete’s

Carbon Footprint

Click to edit Master title styleLCA & Concrete Carbon Accounting

Where does the CO2 come from?

Limestone containsCalcium Carbonate = CaC03

Click to edit Master title styleLCA & Concrete Carbon Accounting

How do we measure it?

▪ Environmental Product Category Rules (PCRs)

▪ Environmental Product Declarations (EPDs)

Click to edit Master title styleLCA & Concrete Carbon Accounting

What are the outputs of a Concrete EPD?

How to reduce CO2

▪ GUL versus GU – 10%

▪ Maximize SCM’s

▪ Specify lowest strength possible

▪ Don’t ask for early strength

▪ Maximize admixture usage

LCA & Concrete Carbon Accounting

Click to edit Master title styleSelf Consolidating

Concrete and Chemical

Slump Enhancement

Click to edit Master title styleACI Self Consolidating Concrete Definition

➢ Highly flowable, non-

segregating concrete that can

spread into place, fill the

formwork, and encapsulate the

reinforcement without any

mechanical consolidation

Click to edit Master title styleCharacteristics of SCC

➢ High fluidity

➢ Takes the shape of any

formwork configuration

➢ High resistance to

segregation or bleeding

➢ No honeycombing!

Click to edit Master title styleHow Much Slump is Too Much Slump?

▪ Any slump enhancement with

water is a receipt for disaster!

Advantages of chemical admixtures

▪ Workability increases up to 230 mm

▪ No negative impacts on W/CM ratio

▪ No negative impacts on scaling

resistance

▪ No negative impacts on chemical

durability

Click to edit Master title styleConclusions

➢ Concrete is a highly versatile product!

➢ Minimum performance requirements exist for every possible

application

➢ Chemical admixtures can dramatically increase the performance of

the concrete in both the hardened and plastic states

➢ Agricultural concrete is highly sustainable and already supports the

use of supplementary cementing materials

Click to edit Master title styleQuestions?

Click to edit Master title styleDo Your Projects Look This Good?