ASTM C78 - Flexural Strength

[@sitinuraisyahjemat9898]

What are the speed testing

[@suhaibahmed3972]

Thank you so much

[@hassanamjad5323]

Whats the length of the beam

[@gabriellastadler7721]

How long should the specimen be in the mold before removing it and curing it?

[@cttparkansas4219]

The specs loosely say up to 48 hours. As a general rule when kept properly between temperatures of 60 to 80 degrees while curing, it is generally safe to strip concrete cylinders and beams the next day, though if its kept in cold temperatures you may want to use up to that full 48 hours to make sure they aren't "green", which is a term to mean it hasn't fully hardened yet.

[@jesusglopez8430]

Thanks for sharing.

[@jetson3851]

Is ultimate load the maximum load or is it the load at constant rate?

[@cttparkansas4219]

Yes you can think of ultimate load as the maximum load. The loading rate has to be between 125 and 175 psi/min (or that would convert to 1,500 to 2,100 lb/min....which would further convert to 25 to 35 lb/sec depending on how your compression machine reads)

[@surkhabalam7684]

Nice video

[@dinkykohli4885]

Sir how many support nblocks we r using

[@cttparkansas4219]

This type of setup has 2 support blocks (that the beam is resting on) and 2 loading blocks (applying the flex load)

[@carlosalcidestupayachimarm5840]

Very helpfull!

[@notachannel3104]

how do we know 3%-6% of estimated maximum load?

[@Sierrablue03]

Read the spec of the job

[@cttparkansas4219]

That depends on what we anticipate the maximum load to be. The whole idea of the 3-6% is to just put enough of the load for the loading/support blocks to be fully in contact with the beam, thus being able to check for gaps using the feeler gauge. As a loose ballpark, typical beams may have a maximum load of between 6,000 to 12,000 (much smaller as compared to cylinders). 3% of 8,000 would be 240. 6% would be 480. So as an approximation, we could say between 200-500 load (which is extremely small) can be applied, but again it depends on what the expected maximum load is.

[@涵紫-w4u]

ok

[@gesyukushibatasou-mansion]

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