When concrete formwork experiences voids or honeycombing, filling the gaps with non-shrink grout is an efficient, cost-effective solution. This material offers durable repair solutions and reduces the need to tear out and replace the entire concrete structure. One of the easiest ways to ensure your non-shrink grout mix will perform well is to use a non-shrink grout admixture, like Fritz-Pak’s NS-7. NS-7 produces a hydrogen gas in the grout mix that allows the material to expand and fill every crevice of the void and reduces shrinkage as the grout sets. Additionally, NS-7 improves the flow of the grout mix, making it more pumpable and easier to place. NS-7 does not contain hazardous materials and comes packaged in our signature water-soluble bags for easy dosing.
How does NS-7 work and produce a nonshrink grout?
It contains an ingredient that generates gas and produces expansion. Expansion occurs before set in order to fill all voids and cavities.
Is the expansion desctructive?
No. Since the expansion is made by gas, it will not be strong enough to break any forms.
Is there any expansion after setting?
What type of gas is generated?
Are there any special guidelines for the application of non-shrink grouts made with NS-7?
Generation of gas starts within 5 minutes of adding water and will continue for approximately 1½ hours. The sooner the grout is placed, the greater the expansion it will give. The grout should not sit more than 1½ hours before it is used.
Does NS-7 work with calcium aluminate cements?
Yes. It is also effective with fast set cements
Does NS-7 contain a water reducer?
For grouts made with NS-7, do I follow standard concrete testing procedures?
No. Compressive strength needs to be tested using restrained cylinders or molds. If not done this way, compression strengths will be lower. See ASTM C 1107 for further reference.
Can I use NS-7 for block fill material?
What are the standards for NS-7?
NS-7 is used to produce non-shrink grouts. It is the grout produced that needs to conform to the specifications. With NS-7 you can produce grouts that conform to ASTM C 1107, Grade "A" Pre-Hardening Volume-Adjusting.
What are the best applications for NS-7?
NS-7 is used to prepare non-shrink grouts used in block filling, hollow core filling, ICF grouting, back filling in tunnels, back filling of pipes and in general for filling voids were low to moderate strengths are required.