General Purpose

By: Golden Bay  06-Dec-2011
Keywords: Residential Construction, Cement, Mortar

Golden Bay Cement's Type GP cement is a premium Portland cement which is used in commercial, industrial and residential construction in New Zealand.

Type GP is a light coloured cement which has earned a reputation for quality and consistency in New Zealand construction circles.

Type GP cement is manufactured under carefully monitored conditions at Golden Bay Cement's Portland plant, near Whangarei. In addition to being the cement normally specified for general construction, Type GP's characteristics have enabled it to be used in a variety of applications which normally call for specialised cements.

Golden Bay Cement's Portland Plant manufactures a range of cements conforming to NZS 3122:2009 and other relevant Standards.


Type GP cement is available in multi-walled paper sacks from Golden Bay Cement stockists and in bulk from the company's Customer Service Centres.


Type GP cement exceeds the minimum specifications given in NZS3122:2009. Manufacture of all Golden Bay Cement products is monitored by the company's IANZ accredited laboratories.

Type GP cement conforms to the requirements of NZS3122:2009 for use with aggreates of low alkali reactivity.

Type GP cement is manufactured by grinding Portland cement clinker and gypsum, and may contain up to 5% mineral cement extender.


Type GP cement is ideal for use in structural concrete, mortars, renders, grouts and cement based products, and can also be used as a general binder for applications such as soil

Supplementary cementitious materials:
Type GP is compatible with Flyash, Silica Fume, and Ground Granulated Blast Furnace Slag conforming to the relevant sections of NZS 3122:2009 Flyash in bulk is available from Golden Bay Cement.

Admixtures for concrete:
Type GP is compatible with concrete admixtures complying with NZS 3122:2009. In hostile environments professional advice is essential to ensure all requirements are met to produce the desired durable product.


Type GP is the cementtraditionally used in construction and industry. It is specified when the special properties of Low Heat of Hydration (temperature rise), High Sulfate Resistance or High Early Strength are not required.

Typical Properties

  Type GP
Relative Density t/m3 3.09
Specific Surface Area m2/kg 330 - 350
Sulphate Content % 2.1 - 2.2
Loss on Ignition % 2.0 - 4.0
Sodium Equivalent % less than 0.60
Chloride Content % 0.01 
Components (nominal)
Portland clinker % 89.5
Gypsum % 3
Mineral Additions * % 7.5
Cement Improver CBA 1115 -

* Mineral additions can be Limestone, Huntly Fly-ash or a combination.

Typical Chemical Properties

Units Portland clinker Limestone GP cement
SiO2 % 22.8 4.5 -
Al2O3 % 4.2 0.5 -
Fe2O3 % 2.3 0.6 -
CaO % 64.8 51.8 -
MgO % 1.0 0.8 -
Na2O % 0.19 0.08 -
K2O % 0.49 0.13 -
Free lime (CaO) % 1.3 - -
Hypothetical Compounds
Lime Saturation Factor % 95.0 - -
C3S % 68 - -
C2S % 14 - -
C3A % 7 - -
C4AF % 7 - -

Typical Performance Properties

  Units GP cement NZS 3122:2009

Setting time

Initial min 105 45 min
Final hr/min 3.00 10.0 max
Soundness mm 1.2  5.0 max
SO3 % 2.2  3.5 max
Compressive Strength (ISO-CEN mortar)
3 days MPa 31.3 -
7 days MPa 45.0 25.0 min
28 days MPa 63.2 40.0 min
Mortar Drying Shrinkage
7 days microstrain 440 -
14 days microstrain 580 -
21 days microstrain 600 -
28 days microstrain 620 750 max

Max Temp rise

°C  - -

Concrete results based on Standard Golden Bay Cement laboratory mix using commercial aggregates, admixtures and a manufactured sand. W/C=.066


Keywords: Cement, Cement Products, Industrial and Residential Construction, Mortar, Portland Cement, Residential Construction,

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If you have queries the Golden Bay Cement Technical Marketing Team would be pleased to be of assistance.