A hollow Concrete Masonry Unit (CMU) wall is being designed. The specified compressive strength of masonry ($f'_m$) is 1500 psi. To verify the materials meet this specification before construction begins, a set of three standard 2-block masonry prisms (built using the proposed CMUs and Type S mortar) is tested in compression according to ASTM C1314.

The prisms have nominal dimensions of $8" \times 8" \times 16"$ (actual width $b = 7.625"$, actual length $l = 15.625"$, actual height $h = 15.625"$). The prisms are tested as completely hollow (un-grouted). The net cross-sectional area of the hollow CMU is 54.0 $in^2$.

The ultimate compressive loads causing failure in the three prisms are: Prism 1: 95,500 lbs Prism 2: 89,200 lbs Prism 3: 101,000 lbs

According to ASTM C1314, a height-to-thickness ratio ($h/t_p$) correction factor must be applied to the calculated strength if the ratio is not exactly 2.0. The actual thickness of the prism ($t_p$) is the width of the CMU ($7.625"$). For an $h/t_p$ ratio of 2.0, the correction factor is 1.00. For an $h/t_p$ ratio of 2.5, the correction factor is 1.04.

Determine the tested compressive strength of the masonry ($f'_m$) and verify if it meets the design specification.

A masonry contractor needs to mix a large batch of Type S mortar on-site. The standard "recipe" (by volume) for Type S is: 1 part Portland Cement (PC) 0.5 parts Hydrated Lime (HL) 4.5 parts Masonry Sand (S)

The contractor is using a standard 1 cubic foot ($1 \text{ ft}^3$) bag of Portland Cement as the base unit for mixing.

If the contractor uses exactly two (2) bags of Portland Cement for a single batch in the mixer, calculate the required volume (in cubic feet) of Hydrated Lime and Sand needed. If a standard 5-gallon bucket holds exactly $0.67 \text{ ft}^3$, how many buckets of sand must the laborers shovel into the mixer?