July week 2 - GRP Quiz

How Well Do You Know GRP? Take the Quiz

Question 1

GRP rebar is significantly lighter than steel rebar. Roughly how much lighter is it?

  1. A) Around 25% lighter
  2. B) Around 50% lighter
  3. C) Around 75% lighter
  4. D) About the same weight

Question 2

True or false: an angle grinder cuts through GRP palisade fencing quickly and cleanly, just as it does with steel.

  1. A) True
  2. B) False

Question 3

The ENGRail modular GRP handrail system was independently tested in January 2026. At the standard 25mm deflection limit, what load capacity did it achieve?

  1. A) 0.9 kN/m
  2. B) 1.5 kN/m
  3. C) 1.657 kN/m
  4. D) 2.4 kN/m

Question 4

GRP scaffold tubes are manufactured to a specific outside diameter so they are compatible with standard steel scaffold fittings. What is that diameter?

  1. A) 42.4mm
  2. B) 48.3mm
  3. C) 51mm
  4. D) 60.3mm

Question 5

What percentage of a standard open mesh GRP grating panel is open space?

  1. A) Around 30%
  2. B) Around 50%
  3. C) Around 70%
  4. D) Around 90%

Question 6

GRP is used in MRI suites and certain defence environments for a specific reason relating to its material properties. Which property makes it suitable?

  1. A) It is fire resistant
  2. B) It is non-magnetic and non-conductive
  3. C) It is lighter than aluminium
  4. D) It is chemically inert

Question 7

True or false: GRP fencing has significant scrap metal value, which makes it a target for metal theft on infrastructure sites.

  1. A) True
  2. B) False

Question 8

Corrosion of steel reinforcement in concrete is a significant global infrastructure cost. Roughly how much does it cost the UK annually in concrete repairs?

  1. A) Around £100 million
  2. B) Around £500 million
  3. C) Over £1 billion
  4. D) Over £5 billion

ANSWERS

Question 1: C. GRP rebar has a density of around 2,100 kg/m3 compared to steel at 7,850 kg/m3. That is approximately 75% lighter, which significantly reduces transport and handling costs on site.

Question 2: B. False. The glass fibres in GRP bind the blade of an angle grinder, making cutting slow, noisy, and highly conspicuous. This, combined with the fact that GRP has no scrap value, makes it a highly effective deterrent against opportunistic theft and intrusion.

Question 3: C. ENGRail achieved 1.657 kN/m at 25mm deflection in independent testing at a UKAS-accredited facility in January 2026. The public assembly loading standard requires 1.5 kN/m, meaning ENGRail exceeds it by more than 10%. Its ultimate load capacity is 7.159 kN/m, a safety factor of 4.77 times the requirement.

Question 4: B. GRP scaffold tubes are manufactured to 48.3mm outside diameter, which is identical to standard steel scaffold tube. They connect directly to Kwikstage, cuplock, and ring-lock couplers without modification or retraining.

Question 5: C. Standard open mesh GRP grating has an open area of around 70%. This allows light transmission, free water drainage, and unrestricted ventilation, which matters considerably in basement plant rooms, underground access structures, and roof-level maintenance platforms.

Question 6: B. GRP is both non-magnetic and non-conductive. In MRI suites, ferromagnetic materials affect image quality and create safety risks near the powerful magnetic field. In sensitive defence environments, GRP creates no magnetic signature and no compass deviation.

Question 7: B. False. GRP has no scrap metal value and cannot be sold at a scrap yard. This removes the financial motivation that drives metal theft on infrastructure sites and is one of GRP fencing’s strongest practical advantages over steel in exposed locations.

Question 8: C. Corrosion of steel reinforcement in concrete costs the UK over one billion pounds annually in repair and maintenance. Because GRP rebar contains no iron and cannot undergo electrochemical corrosion, it eliminates this cost entirely over the life of the structure.

How did you do?

7 to 8: You know your composites. Have you considered a career in technical sales?

4 to 6: Solid knowledge with a few gaps. Worth a closer look at the ECL product range.

0 to 3: The good news is you now know considerably more than you did five minutes ago.

Engineered Composites has supplied GRP products to rail, water, defence, marine, and infrastructure projects since 1986. If a project requires materials that can outperform steel in corrosive, conductive, or demanding environments, speak to the team at engineered-composites.co.uk.