Q1/ A reinforced concrete beam has the following properties: Beam width (b)-300 mm Beam height (h)-600 mm • Effective depth (d) - 525 mm ⚫ Concrete compressive strength (f'c)=27 MPa ⚫ Steel yield strength (fy)=420 MPa . Steel reinforcement area (As) 1473 mm² • Modular ratio (n) = 8.2 Calculate the location of the neutral axis and determine if the section is in the uncracked or cracked stage when subjected to a bending moment of 81 kN m. Use the working stress method.

Note For Problems 9.6-1 through 9.6-5, use the lower-bound moment of inertia for deflection of the composite section. Compute this as illustrated in Example 9.7. 9.6-5 For the beam of Problem 9.4-2. a. Compute the deflections that occur before and after the concrete has cured. b. It the live toad deflection exceeds L360 , select another steel shape using either LRFD or ASD.

A W1422 acts compositely with a 4-inch-thick floor slab whose effective width b is 90 inches. The beams are spaced at 7 feet 6 inches, and the span length is 30 feet. The superimposed loads are as follows: construction load = 20 psf, partition load = 10 psf, weight of ceiling and light fixtures = 5 psf, and live load = 60 psf, A992 steel is used, and fc=4 ksi. Determine whether the flexural strength is adequate. a. Use LRFD. b. Use ASD.

Portland cement concrete consists of what four primary elements?

What is the main value in pre-stressing pre-cast concrete columns?

In Example Problem 12.1, a uniaxial composite material is made into a circular rod Vbith a 1.27-cm diameter from 70 volume percent continuous carbon fibers and 30 volume percent epoxy. The rod is subject to an axial force of 100,000 N. The composite matcrial in Example Problem 12.1 is to be replaced with a less expensive composite made of 70 volume percent continuous E-glass fibers and 30 volume percent epoxy. The elastic moduli are 5 GPa for the epoxy resin and 72.4 GPa fos the E-glass. (a) Compare the elastic modulus, composite strain, fiber and matrix stresses, and density of this composite with the carbon epoxy composite in Example Problem 12.1. Usc the density of UHM carbon, and assume the density of the epoxy is 1.2g/cm3 . (b) Can both the E-glass fiber and matrix withstand the applied force?

List three common categories of stress that must be known before a beam size can be determined.

Note For Problems 9.6-1 through 9.6-5, use the lower-bound moment of inertia for deflection of the composite section. Compute this as illustrated in Example 9.7. 9.6-3 For the beam of Problem 9.3-1, a. Compute the deflections that occur before and after the concrete has cured. b. If the live-load deflection exceeds L360 , select another steel shape using either LRFD or ASD.

A tensile test was performed on a metal specimen having a circular cross section with a diameter 0. 510 inch. For each increment of load applied, the strain was directly determined by means of a strain gage attached to the specimen. The results are, shown in Table: 1.5.1. a. Prepare a table of stress and strain. b. Plot these data to obtain a stress-strain curve. Do not connect the data points; draw a best-fit straight line through them. c. Determine the modulus of elasticity as the slope of the best-fit line.

If the soil-bearing pressure is 1500 psf and the concrete has a strength of 2500 psi, what size pier is needed to support a load of 4600 lb?