otl final - nz concrete contractors

On The LevelOn The LevelOn The LevelOn The Level

In This Issue

Page

Conference 2017 2

Rubber Ruler 3

Site Safe Online Learning 4

Mileage Rates 4

Concrete Supply 5

Code of Practice 6

CCANZ

Best Practice Guide 7 - 8

CCANZ

Ask Alistair 10 - 12

BCITO

Certification 13 - 16

New Members 17

NZMCPA PO Box 302-486 North Harbour Auckland 0751 Ph.: 027 5319940 E: [email protected] Web: mcpa.org.nz _________________________

Major Sponsor of NZMCPA

June 2017

On The LevelOn The LevelOn The LevelOn The Level 2

Conference, AGM & Awards

Registrations and applications are available through

our website link here, or contact Ed at

[email protected] for the forms.

Don’t forget, Conference Early Bird Registrations

close on Friday 14th July so don’t miss out.

Awards Entries are open until Friday 21st July 2017.

Debate

“Technology is Wasted in the Concrete Industry”

We need volunteers for the debate teams on the

Friday night. Contact Kristina on [email protected]

for details.


Rubber Ruler

The season is now mud, cold, and rain. The concrete seems to want to take its time to go off, and we have forgotten the cycle. We went through the same thing twelve months ago at this time.

Perhaps it is just me as I am another year older this year. Is it time for me to start to think about standing aside, and let some new blood have a go? I never thought I would be having to decide about the time that I retire and “hang my trade guns up”.

Passing on our skills is more paramount as we get nearer that magical gold card age of 65 years young. It is quite ironic that we are NOT allowed to ‘discriminate’ by age, but the establishment says we can inherit the “National Super” and cash in and use our Kiwi Saver (if you were wise enough to take the advantage of paying in over the years). The law says one thing, but what do employers think looking after the aging workers?

You are probably reading this and thinking what the hell this opening has got to do with concrete placing. Quite a lot really as the young do not seem to be wanting to line up and take our places. The RR always keeps his views through “rose tinted glasses” and looks on the side of optimism. My statement about an aged trades’ workforce is supported by the Department of Statistics (NZ) report in 2015 that gives our average workers age of 58 years. That to me is too old! It does not matter which way we paint it; you may feel the same as when you were 30, but nature tells your body otherwise. I have discussed this question over the years with you - How do we get young people into our trade? We are still floundering around. You may have attended “talk fests” and we have tried to entice by trade qualifications and recognition. The

stumble of our trade is hard work, lower than expected wages, and working conditions. Youngsters compare these factors to other softer and easier work options.

Politically, I could say I hear the “blue N” party saying bring in the qualified labour, and the “red L” party saying we need better conditions and to get our own people into work.. Not being a drinker, I would say the beer slogan is about “yeah right”. Let’s do what we seem to do the best. Get a committee together and talk some more and wait ‘til after this year’s elections. I have contacts in various ITO’s and the trainee numbers are dropping off. Bluntly that means sign-up and young people flocking to get involved is not happening. The flow on is that ITO’s need numbers to get the cash to run their business. Media and others have said they have found a possible fix; “More females are required to balance up the numbers…” I look at statements like this the same way as when we decided that every loaf of bread sold in NZ will only be “thick and thin”. Whichever way you butter the bread not everyone will like it. If the wages/conditions of the concrete worker was the same as for the similar building trade (with same seniority/time) then we may have applicants lining up. Wage details from the ‘NZ Labour Survey’ show the average rates of pay per hour for concrete trades as $18.66, and builders as $25.43. That is roughly a difference of 36% in parity. I wonder why they are not lining up at our door?

You think you are confused! I know that I am at times, it is probably my age.

Kindest regards

RR


Site Safe Launches Online Learning

IRD - Standard Mileage Rates For Motor Vehicles

The current mileage rate for motor vehicles is 73 cents per kilometre for both petrol and diesel fuel vehicles.

From the 2016-17 income year, different rates apply for hybrid and electric vehicles:

• Hybrid - 73 cents per kilometre.

• Electric - 81 cents per kilometre.

Site Safe has launched its first-ever blended online course.

The not-for-profit membership health and safety organisation has designed a

new course combining the advantages of online and in-class learning, so

trainees will now have even more flexibility when they renew Site Safety Cards

(Passports).

Chief Executive Alison Molloy says the new course will extend workers’ health

and safety knowledge, while also providing companies with another cost-

effective training option.

“ Our latest course, which gives trainees access to a range of online modules as well as in-class time with a health and

safety expert, is a direct result of feedback from the industry. Our new online modules are worker-focused, and allow

trainees to choose the topics that are directly relevant to the real-life risks they face on site.”

The Passport Plus - Flexi (Online + Classroom) is now open for online bookings and will be available at a special

introductory price for the first six months.

Trainees select any two modules from a regularly updated online library, which currently includes: asbestos, noise,

worker basics, manual handling, mobile plant and electrical safety. With the addition of the Passport Plus – Flexi, Site

Safe now offers a total of four new renewal options.

• Passport Plus - Flexi (Online + Classroom) 2hrs in-class & 2 online modules

• Passport Plus - Tools and Plant 4hrs in-class

• Passport Plus - Height 4hrs in-class

• Passport Plus - Worker Health 4hrs in-class

Successful completion of any Site Safe course, including

one and two-day courses, or entry-level Foundation

Passports, will renew Site Safety Cards/Passports. To learn

more, visit https://www.sitesafe.org.nz.


Concrete Supply Issue In Auckland

The Auckland market is experiencing its strongest growth in over 40 years, and with this brings extreme

pressure points around the supply of concrete. There’s a lot of noise out there, and the issue has been a

topical discussion around the NZMCPA boardroom table for some time.

Rest assured, the NZMCPA is working behind the scenes to address this matter and we aim to provide

possible solutions to an issue that doesn’t appear to be going away anytime soon. What we can tell you at

this point in time, is that we are partnering with the NZRMCA to address some of the issues that our Members

are experiencing, such as lead times, driver shortages, delayed deliveries, and the quality of this perishable

product once it hits the site.

We’ve recently canvassed people across the industry both regionally and nationally, from concrete

contractors, builders, drivers, to dispatchers. The feedback indicates that the concrete shortage problem is

largely confined to the Auckland region. We hear your frustrations, and while there is no quick fix to the issue,

we can reinforce the recommendations proposed by the NZRMCA via CCANZ which aim to minimise

disruptions to your business.

The NZMCPA has formed a subcommittee to focus on this issue, led by Marty Black and supported by Brad

Robertson, Stu Packard and Bernie McIntosh. This committee will aim to channel communications/feedback

between Placers and Ready-Mix Companies in order to address the problems.

PLANNING is key, and will be for the

future. Placing orders well in advance

will certainly help to reduce some of

the issues.

Back in November 2016, the NZRMCA

published an article regarding ‘Ordering

Practices Key to Reducing Concrete

Delays’. Please take the time to read this

article and implement some of these

recommendations in the day to day running

of your business [click for the link]

We were recently given the opportunity to

address the NZRMCA meeting in Auckland

and we presented our case to about 20 of

their members. This has resulted in some

positive steps being considered in an effort to

improve the situation. A report on that

meeting will be sent to members shortly.

The NZMCPA will keep you updated on how

we are progressing with this issue and in the

meantime, please don’t hesitate to contact

us if you have feedback/input on this topical

problem.

Martin Black

NZMCPA Board Member

NZ Interna�onal Conven�on

Centre, Auckland 2017

NZ International Convention Centre, Auckland 2017


NZMCPA Develops Code of Practice

A ‘Code of Practice’ has been created and developed by the NZMCPA Board, with support from the Cement &

Concrete Association of NZ (CCANZ), the NZ Ready Mix Concrete Association (NZRMCA), Members, and other

key industry Associates.

The development of this document was prompted in part by the Pinto coverage which was aired on TV3 – Story

last year. Current circumstances have identified that Concrete Contractors have little/no specifications for the

placement of domestic driveways. Therefore, the need to develop this document was escalated.

As Concrete Contractors are accountable

for the placement of concrete, it was

imperative we took the lead with

developing this document for our

industry.

The Code of Practice is an important

document that involves our Members and

the document will be sent to print shortly.


The construction of defect-free concrete ground

floor slabs, also called ‘Slab-on-Grade’ or ‘Slab-

on-Ground’, requires experience and skill. The

concrete placer has to contend with a number of

variables, including changeable weather,

concrete properties and ground conditions.

Defects in concrete slabs or pavements

represent the majority of all concrete defects,

resulting in significant costs for repair and

associated disruption in the use of the floor or

pavement.

To assist in this area, the Cement & Concrete

Association of NZ (CCANZ) and the NZ Ready

Mixed Concrete Association (NZRMCA) have

updated Technical Report (TR) 09 Surface

Delamination in Slab-On-Ground Construction

with Technical Report (TR) 16 Best Practice in

Casting Concrete Ground Floor Slabs and

Pavements.

TR16 outlines the most common defects in

concrete ground floor slabs and best practice to

help avoid them. It is particularly relevant to

specialist concrete placers but also to

supervisors of concrete slab construction.

Commercial slab construction is often carried out

by specialist subcontractors. Clients and main

contractors should satisfy themselves that the

subcontractor has the necessary skills and

experience to undertake the slab in question.

Most defects in concrete ground floor slabs and

pavements are cracks in the slab. Cracks may

merely be aesthetically annoying. However, they

have the potential to be more serious -

threatening the durability of a slab or the surface

wear performance.

Best Practice Guide to Casting Concrete Ground Floor Slabs and Pavements


Cracking in concrete can be reduced through good design, planning, and skilled execution. TR16

details five common defects in concrete slabs, explaining why they occur and how to avoid them.

They are:

• Plastic Shrinkage Cracking

• Delamination

• Thermal Cracking

• Drying Shrinkage Cracking

• Plastic Settlement Cracking

Login into the NZMCPA website to download a copy – www.mcpa.org.nz


Ask Alistair CCANZ STRUCTURAL ENGINEER ALISTAIR RUSSELL LOOKS AT HOW TO GET THE BEST OUT OF YOUR GROUND FLOOR SLAB BY GETTING IT TO CRACK WHERE YOU WANT IT TO.

SAW CUTS

Most conventional ground floor slabs are saw cut at between 3 and 5m centres. The cuts are provided in an attempt to

force the concrete to crack where the designer intends. Although often specified, the reason for cutting the slab is often

not fully understood. In this article we explore this ubiquitous construction method by providing answers to some

frequently asked questions.

WHY DO WE SAW CUT GROUND FLOOR SLABS?

As concrete dries, it shrinks. If the slab is restrained at the edges, or by friction along the base, tension stresses will

develop in the concrete over time. If these exceed the tensile capacity of the concrete, it will crack. Tensile stresses also

develop in the concrete due to induced bending moments created by curling of the slab. Joints, and a saw cut is a type of

joint, are provided in an attempt by the designer to direct where the concrete will crack.

WHY ARE THEY NORMALLY PROVIDED AT 3 TO 5 M CENTRES?

If a slab is unreinforced,

NZS 3604:2011 Timber-Framed

Buildings requires saw cuts be

provided at 3m centres. For

conventionally reinforced slabs,

the spacing between saw cuts is

typically limited to between 4 and

5m. Why do we need so many

saw cuts? Calculations are

sometimes performed evaluating

the expected tensile stresses in a

slab as it shrinks, created by

friction along the base. These

calculations usually assume only

axial stresses are developed, and

generally show that the joints can

be placed considerably further

apart than 5m.

However, these calculations fail to

consider that a slab can often only lose moisture from the top surface. This creates a shrinkage gradient that causes the

slab to curl. Although the amount of curling might be small, the tensile stresses it develops in the slab are large. Unless

precautions are taken to avoid slab curl, saw cuts in conventionally reinforced slabs should be provided at 4-5m centres.

SHOULD I CUT EVERY SECOND REINFORCING BAR CROSSING THE SAW CUT?

Saw cut joints are normally designed as tied joints located between free isolation joints. Shrinkage movement is expected

to be concentrated at the free joints, and the saw cuts are provided to prevent unsightly random cracking between the

free joints. The saw cuts are not expected to open up. For this common design situation, reinforcement crossing the saw

cut should not be cut. The reinforcement is placed in the ground floor slab to control shrinkage cracking. It is normally

proportioned to ensure that if the concrete were to crack, the reinforcement across the crack would not yield – therefore

ensuring that the crack width remains small. If some of the reinforcement is cut at the location of a saw cut, the

reinforcement might yield at this location if the concrete cracks, meaning that the cuts will open up more than is strictly

necessary. Continued next page


WHEN SHOULD THE CONCRETE BE CUT?

The preference would be to use an early entry saw and cut the slab within 6-8 hours of placement. Cutting early means the

risk of random cracking from restrained early thermal contraction is reduced.

If a conventional diamond edged circular saw is used, the slab should be cut as soon as it is sufficiently hard to get a clean

cut (typically within 24 hours).

HOW DEEP AND WIDE SHOULD THE SAW CUT BE?

A saw cut should be one-quarter the thickness of the slab, though this depth can be reduced if an early entry saw is used.

The width is dependent on whether the cut will be sealed with a flexible sealant. If the joint is not going to be sealed, a single

pass of the saw blade is sufficient. This typically creates a cut approximately 5mm wide. If the joint is to be sealed, the

practicalities of installing the sealant and the movement that is expected across the joint need to be considered. The more the

expected movement, the wider the joint will need to be. To be effective, a de-bonding tape, or backing rod, is required in the

joint to prevent the sealant from sticking to the bottom of the cut. This means that a practical minimum width for a sealed joint

is 10mm.

CAN THE NUMBER OF SAW CUTS BE REDUCED OR ELIMINATED?

Yes, but you will need to explore using expansive cements or post tensioning.

Continued next page


JOINTS IN SLABS

WHAT IS AN ISOLATION JOINT?

An isolation joint is a joint where no tensile or compressive force can be transferred across the joint. In other words, the joint is

free to open and close. The joint may or may not be doweled to assist shear transfer across the joint (more on this later).

DO I NEED EXPANSION JOINTS?

Yes. It is important to recognise that concrete expands on heating, and this expansion needs to be accommodated. It is not,

however, typical for on-ground slabs to have joints that can accommodate expansion from day one. All joints open as

shrinkage occurs, allowing some expansion to be accommodated. The norm would be to provide saw cuts and construction

joints, which after some shrinkage can accommodate expansion of the concrete.

Concrete roads are essentially on-ground slabs that are exposed to the elements. The design philosophy for jointed

pavements is as described above, and excellent performance is achieved. Expansion joints that allow expansion from an early

age will be required when using expansive cements, or for elevated structures exposed to the elements such as bridges and

upper floors of car parking buildings.

HOW SHOULD I LAY OUT MY JOINTS?

Sensible layout of the joints will greatly reduce the chance of unwanted random cracking. Given its importance, the layout of

joints should be shown on the drawings.

When planning the joint layout, first look for re-entrant corners. These represent stress raisers, and are the most common

position for cracks to propagate from. It is almost possible to guarantee that a crack will form at this location so ignore them at

your peril. Figure 1 shows a sensible layout for a re-entrant corner.

Think carefully about penetrations and box-outs. If square, these can create sharp re-entrant corners that trigger cracks.

SHOULD I DOWEL AN ISOLATION JOINT?

The benefits of an isolation joint are:

♦ You may be able to reduce the floor thickness as load is transferred across the joint.

♦ The risk of creating a step between adjacent slabs due to differential warping is eliminated.

For trafficked joints, particularly when forklifts are involved, it is highly desirable to dowel the isolation joints.

SHOULD I ARMOUR THE EDGE OF THE JOINT?

Tied joints, such as saw cuts, are not normally armoured along their edge. The reinforcement that ties the joint typically

prevents it from opening up. Sufficient durability can normally be achieved by the use of concrete with an appropriate

compressive strength.

At isolation joints, the joint will open up as the concrete shrinks. Where the joint is trafficked, particularly with solid-tyred

forklifts, it is sensible to provide some armouring to the edge of the joint. This is typically achieved by using angles cast into the

concrete or by using proprietary systems that incorporate steel plates.

Ar�cle first appeared in CCANZ Concrete magazine Vol 59. Issue 2.


BCITO Concrete Qualifications

Did you know that BCITO offers many different qualifications specifically designed for different industry roles? Depending on what area of the industry you’re working in there’s sure to be one that suits your role in particular.

Here’s the full rundown of what’s on offer and what topics are covered in each apprenticeship. You should seriously consider the option that’s tailored just for you if you’d like to become a qualified professional or to upskill your team.

Compulsory Elec�ves

For those new to the concrete industry

looking to gain solid all-round industry

knowledge and skills

Na�onal Cer�ficate in Concrete Core Skills

(Level 2)

Tool use

Concrete produc�on

Concrete tes�ng

Health and safety

Environmental prac�ces

Problem solving

Safe working prac�ces

Time management

First aid

Communica�on

Construc�on equipment

For Concrete Construc�on workers

Na�onal Cer�ficate in Concrete

Construc�on (Level 4)

Health and safety

Construc�on equipment

Construc�on processes

Installing precast components

Codes of prac�ce and legisla�on

Placing and curing concrete

Repairing exis�ng concrete structures

Measuring techniques

Scaffolding and working at heights

Li0ing equipment

Use of concrete moulds

Confined spaces

Tes�ng concrete

For those who are involved in Concrete

Produc�on:

Na�onal Cer�ficate in Concrete Produc�on

(Level 3)

Health and safety

Concrete industry prac�ce

Concrete materials

Use and maintenance of equipment

associated with concrete produc�on

Handling orders and produc�on and

ready-mixed concrete

Tes�ng concrete

Confined spaces

Forkli0 driving

For Masonry Product Producers

Na�onal Cer�ficate in Concrete Product

Manufacture (Level 3)

Knowledge of the masonry product

manufacturing process

Safety

Plant and equipment

Make masonry products

Curing concrete

Tes�ng products

Secondary processing

Ordering and dispatching

In-depth safety knowledge


For those working in Placing and

Finishing Concrete

Na�onal Cer�ficate in Concrete (Placing

& Finishing) Level 3

Health and safety

Measurement

Placing and finishing specific types

of decora�ve concrete

Concrete industry opera�ons, plant

and equipment

Site prepara�on

Curing

Reinforcing

Cu5ng and drilling

Placing and finishing specific types of

decora�ve concrete

Tes�ng

Defects and remedial work

Specified flat concrete

For those involved in Sawing and Drilling

concrete

Na�onal Cer�ficate in Concrete

Construc�on (Sawing & Drilling) (Level 3)

Health and safety

Concrete industry opera�ons, plant

and equipment

Knowledge of slurry control

Performing sawing and drilling

opera�ons on site

First Aid

Confined spaces

Performing deep floor, wire or track

mounted sawing opera�ons

Performing large core and deep

drilling opera�ons

For those who manufacture concrete

pipes:

Na�onal Cer�ficate in Concrete Product

Manufacture (Pipe) (Level 3)

Reinforcing and cast-ins

Producing concrete

Cas�ng cylinders

Curing concrete

Checking and fixing

Making pipes including: Jacking;

Rubber ring jointed; Inspec�on

chambers; Flush joint; Skid rings

Machinery includes: Plant and

equipment Opera�ng overhead

cranes

Moving and storing includes:

Storing and dispatching; Receiving,

storing and maintaining material

Confined space entry

For those working with Precast Concrete

Na�onal Cer�ficate in Precast Concrete

(Level 3) with strands in Structural,

Prestressing, Precast & Tradi�onal Tank

Health and safety

Specifica�ons

Moulds and de-moulding

Environmental management

Plant and equipment

Fabrica�on and reinforcing

Curing and remedial work

Handling, li0ing and transport

Confined space entry

Tes�ng

Orders for materials and products

Manufacture and fabrica�on of

moulds

Cu5ng and drilling concrete

Crane opera�on

Structural precast - Manufacturing

precast concrete panels, beams,

columns and stairs

Prestressing - Manufacturing

prestressed beams, columns,

flooring units and panels

Precast tank - Manufacturing precast

concrete tanks

Tradi�onal tank - Manufacturing

tradi�onal concrete tanks


With unprecedented levels of construction activity generating an abundance of new opportunities for concrete businesses around New Zealand, it’s important to ensure you keep up with demand.

Getting enrolled or involved in training allows you to:

• Add value to your business and your people

• Give back to your industry

• Improve skills

• Build a positive workplace culture

Experience Recognition

As well as apprenticeships for those new to the concrete industry, BCITO can also deliver these qualifications in a way that suits those who already have skills in concrete. That’s called Experience Recognition - where BCITO may be able to recognise existing experience. You or your staff may be able to get formally qualified through this delivery method in a much shorter timeframe if you’ve been working in the concrete industry for a while now.

If you’re an employer interested in taking on a new apprentice, you’d like more detailed information about how apprenticeships work or want to know more about Experience Recognition, contact BCITO today on 0800 4BCITO (422 486) or visit www.bcito.org.nz/concrete

Image: BCITO


Paveco Ashburton Ltd.

Tony and Lynn Worsfold have experience in the concrete industry spanning over 32 years. They founded Concrete

Plus in Christchurch and then went on to form Paveco Ashburton Ltd in 2003 which began leading the way with

concrete contracting in the Ashburton/Mid Canterbury District.

Fifteen staff work for the company and they specialise in installing concrete driveways, patios, paths, entrance ways,

tennis courts, concrete pool surrounds, house floor slabs, shed floor slabs, commercial floor slabs, wintering barns,

silage bunkers, dairy platforms, feed pads and dairy yards.

Aardvark Concrete Services (2000) Ltd.

Aardvark Concrete Services is a

specialist concrete pumping

company covering the Greater

Wellington and Taranaki regions.

They do all types of concrete

pumping for civil engineering

projects, commercial and residential

buildings. They also do a wide

variety of domestic work including

driveways, patio areas and house

slabs. Aardvark’s work

encompasses a wide and varied

range of concrete services from

exposed aggregate driveways to

spraying concrete walls.

Established in 1999, Aardvark

Concrete now employs 26 full time

staff in the Wellington and New

Plymouth areas. Aardvark has 28

Pumps available for use which help

provide the expertise and resources

to successfully undertake any size

project.

Aardvark Concrete Services has a

large range of Boom and Line

Pumps, Speciality Spray Concrete

Pumps and also Electric Grout

Pumps. Collectively Aardvark has

229 years of industry knowledge in

the company so they see

themselves as a market leader in

this industry and well prepared for

any project.

New Members

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