Title: Air Content of Freshly Mixed Concrete by Volumetric Method Purpose:
*To determine the air content of the concrete by using the volumetric method, which affects the workability, durability, and strength for proper proportioning.
* Portland Cement Mix
* Air Meter Type B, consisting of a bowl and top section
* Tamping Rod
* Strike-off Bar
* Measuring Cup
* Pouring Vessel
* Isopropyl Alcohol
* Course Aggregates
* Fine Aggregates
* Mixing Tub
* Mix concrete (water, Portland cement mix, aggregates).
* Place mix inside bowl in three equal layers.
* Rod each layer 25 strokes with tamping tod, distributing the stroke across the section of each layer.
-First layer full depth
-Second and Third layer to penetrate underlying layer approximately 1 inch. * Tap around contained 10-15 with mallet after rodding each layer. * Strike off excess concrete until level with the top of container. * Clean the rim of the base.
* Clamp top section of bowl, insert funnel, and add water until it appears in the neck. * Remove funnel and use syringe to level out bottom of meniscus with the zero mark, then place screw cap on tightly. * Invert and agitate the unit until concrete loosens at the base. *After air rises to the top, take off the cap and add in 1 cup portions (using syringe), proper amount of isopropyl alcohol to dispel foam at surface of the water. (Capacity of cup is .1% of the volume of the bowl) * Record reading of the liquid in the neck to the bottom of meniscus to the nearest .1% * Percent air content is the previous recording+the amount of alcohol used.
Air Content using the volumetric method-1.6%
In order to determine the percent of air we followed the procedure using the volumetric method and ended with an air percent of 1.6%. I believe that we used a slightly larger amount of water then what was...
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