Material Matters - Spring 2018 - 32

AROUND THE CONCRETE INDUSTRY
By Jeremy Lockhart
New Enterprise Stone & Lime Co., Inc. and Co-chairman
NYMaterials Concrete Technical Committee

Residential Concrete
AS I WRITE this, it is only the end of January

wonder if we are doing everything we can to

of 3500 psi (24 MPa) at 28 days for moderate

and spring can't get here soon enough! For those

educate our contractors, the public and pro-

freezing-and-thawing exposure, and 4500 psi

of us in the Quality Control, Technical Services,

tecting our owners from unwarranted liability.

(31 MPa) for severe freezing-and-thawing expo-

Operations and Sales departments we know

ACI 332.1R "Residential Concrete

sure (Table 2.1). For such conditions, the slump

that the Spring is accompanied by contractors

Construction" states that "Driveways, curbs,

should be as low as practical, with a maximum

and homeowners calls and emails about; "bad

walkways, patios, porches, steps and stairs

of 5 in. (130 mm).

loads of concrete," "spalling or spalding," "sur-

exposed to weather and garage floors, slabs"

Concrete slabs should receive at least 30 days

face flaking" driveways. Many of us attended the

are to be a 4500 PSI and a 5" max slump in

of air-drying time after the moist-curing period

NYMaterials Technical Conference last March at

severe climates that face freeze thaw and

and before exposure to deicing Chemicals.

Hudson Valley. One of the comments that stuck

de-icing chemicals.

The application of deicing chemicals
should be avoided during the first winter

with me personally (and wish I had it on record-

This is not a new spec from ACI as it was

ing) was the speaker from the FHWA who made

amended in 2006. So why 12 years later do

the statement; "We all see and know that the

contractors place 80 percent of their residen-

As we meet in our technical conferences

advancements in de-icing chemicals is outpacing

tial flatwork at a lower PSI of 4000 or below?

and meetings we discuss topics such as: how

the advancements in cements and concretes."

In general, concrete slabs-on-ground should

do we get engineers to be more consistent,

I do not disagree with the statement but I do

have minimum concrete compressive strengths

flexible and write better specifications, how

following placement.

RESIDENTIAL CONCRETE CONSTRUCTION

332.1R-9

Table 2.1 - Minimum compressive strength ƒ'c at 28 days and maximum slump of concrete
Type of location of
concrete construction

Weathering probability*

Maximum
slump, in. (mm)†

Negligible ƒ'c , psi (Mpa)

Moderate ƒ'c , psi (Mpa)

Severe ƒ'c , psi (Mpa)

Type 1: Walls and foundations
not exposed to weather. Interior
slabs-on-ground, not including
garage floor slabs

2500 (17)

2500 (17)

2500 (17)‡

6 (150)

Type 2: Walls, foundations, and other
concrete work exposed to weather,
except as noted below

2500 (17)

3000 (21)

3000 (21)

6 (150)

Type 3: Driveways, curbs,
walkways, patios, porches, steps,
and stairs exposed to weather and
garage floors, slabs

2500 (17)

3500 (24)

4500 (31)

5 (125)

*Exposure class can be determined by the weather probability map in Fig. 2.7.
†Slumps greater then shown can be achieved by the use of a mid-range or high-range water-reducing admixture.
‡

Concrete in these elements that will be subject to freezing and thawing while under construction should be air entrained.

32 Material Matters * Spring 2018



Table of Contents for the Digital Edition of Material Matters - Spring 2018

Chairman’s Message
President’s Report
Legislative Update
Counsel’s Corner
Membership Benefit
Member KUDOS
Work the Problem
2017 Asphalt Pavement Showcase Award Winners
One Company’s Efforts to Set up an Asphalt Plant
An Interview with NYSDOT’s Don Streeter
Residential Concrete
Welcome New Members
Material Matters - Spring 2018 - Intro
Material Matters - Spring 2018 - cover1
Material Matters - Spring 2018 - cover2
Material Matters - Spring 2018 - 3
Material Matters - Spring 2018 - 4
Material Matters - Spring 2018 - 5
Material Matters - Spring 2018 - 6
Material Matters - Spring 2018 - Chairman’s Message
Material Matters - Spring 2018 - 8
Material Matters - Spring 2018 - President’s Report
Material Matters - Spring 2018 - Legislative Update
Material Matters - Spring 2018 - 11
Material Matters - Spring 2018 - Counsel’s Corner
Material Matters - Spring 2018 - 13
Material Matters - Spring 2018 - 14
Material Matters - Spring 2018 - 15
Material Matters - Spring 2018 - 16
Material Matters - Spring 2018 - Membership Benefit
Material Matters - Spring 2018 - 18
Material Matters - Spring 2018 - Member KUDOS
Material Matters - Spring 2018 - 20
Material Matters - Spring 2018 - Work the Problem
Material Matters - Spring 2018 - 22
Material Matters - Spring 2018 - 23
Material Matters - Spring 2018 - 2017 Asphalt Pavement Showcase Award Winners
Material Matters - Spring 2018 - 25
Material Matters - Spring 2018 - One Company’s Efforts to Set up an Asphalt Plant
Material Matters - Spring 2018 - 27
Material Matters - Spring 2018 - An Interview with NYSDOT’s Don Streeter
Material Matters - Spring 2018 - 29
Material Matters - Spring 2018 - 30
Material Matters - Spring 2018 - 31
Material Matters - Spring 2018 - Residential Concrete
Material Matters - Spring 2018 - 33
Material Matters - Spring 2018 - 34
Material Matters - Spring 2018 - Welcome New Members
Material Matters - Spring 2018 - 36
Material Matters - Spring 2018 - 37
Material Matters - Spring 2018 - 38
Material Matters - Spring 2018 - cover3
Material Matters - Spring 2018 - cover4
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