PLEASE NOTE: I am doing some small projects around the yard involving concrete and cement in order to help better understand concrete for when I have bigger projects. I understand I do not need skyscraper/Highway grade concrete for fence posts.

The Job: Putting up a couple of 10+ foot railroad ties that will each hold a 8'x8' home-made gate that will end up weighing ~100+lbs each. I want these railroad ties to never....ever move/sag/slump. Solid as a rock.


I have been searching around not just the internet, but around town the last couple of days trying to find either "flyash" or metakaolin to add to my concrete to make it stronger. I have had no luck, hardly anyone even knows what the heck I'm talking about and there appear to be no suppliers in central CA. I am frustrated, yes.

So i had a fantastic solution! (can you sense my sarcasm?)
I'll buy some ready mix at Lowes and an a bag of Portland cement and just add a couple small scoops to each back of ready mix!
Ready mix: Shop QUIKRETE 80-lbs Pro Finish Concrete Mix at Lowes.com
Cement: Shop Basalite 94-lbs V Portland Cement at Lowes.com


Will this make the concrete stronger and last longer?

Thank you very much.

 

The width of the conrete and depth make the posts solid and higher strength will make little difference. All the concrete has to hold together and it does need any more strength the a 3000 psi remixed, but you can add some extra cement as a "sweetener" to make you sleep better. Just use enough water for it to mix since the California soils can slow curing if you just go the dry way and hope you get enough water into the mix to cure.

Dick

 

Good point, I'm not too worried about making myself feel better, I actually want to know what works and what doesn't so I can know better.


The ties will be placed ~24" deep, and are 7"x9" in size.

Thank you.

 

Whoa... only 24" deep but 10' long? The rule of thumb for fence posts and such is 1/3 of the total length should be in the ground.

 

That sounds like a good rule of thumb to me, and although I don't like the idea of losing height, I will seriously consider digging deeper, it is not too late to do that. Thanks for the advice.

 

A quick correction in terms: "Ready mix" is typically the stuff that's batched elsewhere, and then delivered in a big truck having a rotating round thing (a drum). The stuff you buy in bags at any big box store is usually called a bagged concrete mix.

Unless you're in love with the look and smell of creosote, you might give some more thought to your choice of gate post material. Creosote has a habit of bleeding through any paint or stain you choose to cover it with, so possibly some preservative pressure-treated timbers would be a better choice. Most preservatives will take paint or stain after the members are allowed to age a bit.