13-140-100 Stress limitations based upon net section.

   All stress limitations given in SCPI 1969 and NCMA 1970 and all sectional properties shall be based on the net section of the masonry.

(Prior code § 71-5)

13-140-110 Strength of engineered masonry.

   The strength of engineered brick and concrete masonry fm shall be verified by field tests made in accordance with Section 4.2 of SCPI 1969 for engineered brick masonry and Section 3.2 of NCMA 1970 for engineered concrete masonry. A minimum of one field test specimen shall be made during construction for each 2,000 square feet of wall. A minimum of two tests shall be made for each building, one at the start of construction and one when at least 50 percent of the masonry has been completed.

(Prior code § 71-6)

13-140-120 Minimum thickness.

   (a)   Exterior engineered brick or concrete masonry both load-bearing and non-load-bearing walls shall have a minimum nominal thickness of six inches.

   (b)   Interior engineered brick and concrete masonry load-bearing walls shall have a minimum nominal thickness of four inches and shall be capable of sustaining a horizontal uniform pressure of not less than five p.s.f. without exceeding the allowable tensile stresses of SCPI 1969 and NCMA 1970 respectively.

(Prior code § 71-7)

13-140-130 Grout placement in engineered brick masonry.

   In addition to the requirements of Section 5 of SCPI 1969, the following requirements shall apply to the placing of grout in engineered brick masonry:

   (a)   All joints or spaces designed to receive grout shall be solidly filled. The grouted longitudinal joints shall be not less than three-fourths inch wide. Mortar “fins” protruding from joints shall be removed before placing grout.

   (b)   When the least clear dimension of the longitudinal vertical joint or core is less than two inches, the maximum height of grout pour shall be limited to 12 inches. When the least clear dimension of the longitudinal vertical joint or core is two inches or more, the maximum height of grout pour shall not exceed 48 times the least clear dimension of the longitudinal joint or core for coarse grout nor 64 times for fine grout, but shall not exceed a height of 12 feet. Grout shall be agitated or puddled during placing to insure complete filling of the grout space.

   (c)   When grouting is stopped for one hour or longer the grout pour shall be stopped one and one-half inches below the top of a masonry unit. Masonry bonders (headers) shall not be used, but metal wall ties may be used to prevent spreading of the wythes and to maintain vertical alignment of the wall.

(Prior code § 71-8)

13-140-140 Grout placement in engineered concrete masonry.

   In addition to the requirements of Chapter 4 of NCMA 1970, the following requirements apply to the placing of grout in engineered concrete masonry:

   (a)   All engineered concrete masonry shall be built to preserve the unobstructed vertical continuity of the cores to be filled with grout. Mortar “fins” protruding from joints shall be removed before placing grout.

   (b)   The minimum continuous clear dimensions of vertical cores shall be two by three inches. In filling vertical cores, the grout pour shall not exceed four feet in height unless cleanouts are left open at the bottom masonry course of each core to be reinforced and such cleanouts closed only after inspection of the core space and the setting of vertical reinforcement in fixed position.

   (c)   Grout shall be rodded or puddled during placement to insure complete filling of the core. When grouting is stopped for one hour or longer, the grout pour shall be topped one and one-half inches below the top of a masonry unit.

   (d)   Horizontal beams may be built of reinforced hollow masonry, using channeled units to permit horizontal reinforcement to be placed in the desired position. The top of the unfilled cores below such horizontal beams shall be covered to confine the grout fill to the beam section. No materials shall be used which destroy the bond between courses. Grouting of beams over openings shall be done in a continuous operation. All grout shall be puddled in place to insure complete filling of cores and encasement of reinforcement.

(Prior code § 71-9)

13-140-150 Minimum temperature to be maintained.

   Engineered brick and concrete masonry shall not be built when the temperature is below 32 degrees Fahrenheit on a rising temperature, or below 40 degrees Fahrenheit on a falling temperature, unless adequate precautions are taken to maintain a minimum temperature of the completed masonry and the ambient air of 40 degrees Fahrenheit for a period 48 hours if Type M or S mortar is used and 72 hours if Type N or O mortar is used. Those periods may be reduced to 24 and 48 hours if high early strength cement is used.

(Prior code § 71-10)