30 newton concrete

thomasthomas19

hi , i,m building a small garden wall and need to know the mixing ratio for 30 newton concrete for foundation , cement , sand , gravel, water.

thanks thomas

Poor Uncle Tom

Concrete doesn't achieve it's gradable strength until beyond 28 days after pouring and can be influenced by a number of factors like,
1. the conditions of storing for cement,
2. type and size and quality of agrigates,
3. amount and quality of water,
4. conditions of drying, etc.,

As a general rule to achieve 30N concrete the mix should be 1 cement:0.5 sand:2 gravel and the mix should have:
1. a maximum water cement ratio of 0.45,
2. a workability of 50 - 75mm slump,
3. maximum agrigate size of 20mm,

much more detail is found in IS 10262-2009.

If you are not sure about any of the above and you require a 30N grade concrete, you could order it specifically from a suppliers. You could also ask if they would sell you a dry mix for you to mix on site.

thomasthomas19

thanks for that , i have mixer and sand ,gravel at house , so ill just mix it myself , just need 2 metres.

p.s , out of interest for further projects, what is ratio of 20 and 25 newton concrete

thanks again

Poor Uncle Tom

For a Grade 10N use a mix of 1:3:6
for a Grade 15N use a mix of 1:2:4
for a Grade 20N use a mix of 1:1.5:3
for a Grade 25N use a mix of 1:1:2