North Region Construction - Project 02A2121 Construct Fish Passage



Minor B


Bid Date


County Route PM/KP



Construct Fish Passage

Bidder Inquiry / Response

Inquiry #1:

I haven’t had any projects calling out for a 6000 psi in 28 days meeting the section 90 for Caltrans cementitious requirements. Generally the minimum compressive requirement is 4000 psi with the ratio of the quantity of free water to the quantity of cementitious material that must not exceed 0.40. Is there any way to reduce the minimum compressive requirement to 4000 psi in 28 days on this project? If we need to meet the strength requirement of 6000 psi in 28 days we will need to increase the cementitious greatly which will also creates more issues with the extended travel time to the project due to the heat of hydration.

Under section 90-1.01D(5)(a) For concrete with a described 28-day compressive strength greater than 3,600 psi, 42 days are allowed to attain the strength described.

Except for concrete specified to be in freeze-thaw area, 56 days are allowed to attain the strength described if the cementitious material satisfies the following equation.

Is this 56 day strength requirement an option?

Please let me know if there is any way to modify or if we need look into other mix options.


(BI#1)- refer to section 1-1.09 of the special provisions. Please bid per current contract documents