The maximum size of the conduit or pipe shall NOT exceed _______ of the thickness of the concrete. - correct answer 1/3 Which of the following tests for concrete is conducted at the site/field? - correct answer Color Test Explanation: Rest of the above are laboratory tests. If the concrete compressive strength specified is less than 3600 psi, it has the option of being tested at 28 days and is able to accept the concrete if it attains ___________ percentage of the minimum required strength. - correct answer 85 If the admixtures are used in concrete for the purpose of delayed setting and hardening of concrete, they are called _____________? - correct answer Retarders Which of the following are the general types of vibrating needles that are in use? - correct answer ALL ANSWERS! -Internal vibrators -Immersion vibrators -Surface vibrators Concrete proportioning is done based on the facilities available at the site. Which are the general proportioning methods used for concrete? - correct answer ALL OF THESE -Surface area method -Mix design based on flexural strength -Maximum destiny method The minimum cementitious material that is required for concrete bridging deck is ______________lbs/cu yd. - correct answer 675 The amount of free water used in concrete shall not exceed ____________ pounds per cubic yard of concrete. - correct answer 310 Explanation: If the SCM are added, it can be increased to 20 pounds per each required 100 pounds of cementitious material in excess of 550 pounds per cubic yard. If the concrete curbs are to be constructed over the existing pavement, _______________ are used to fix them to pavement. - correct answer Steel dowels Which of the following is NOT an example of blended cement? - correct answer Combination of silica fume and chlorine fluoride Explanation: Blended cement is a combination of either Type || or Type V cement with any of the SCM Which of the following is a line at which the face of the curb meets the top of the payment? - correct answer Control Joint Which of the following is NOT used as concrete chemicals? - correct answer Abrasion bonding compound Explanation: Concrete curing compound and polymer bonding agent are both concrete chemicals. The admixtures that are used in concrete to improve durability in freeze/thaw environments are ________________. - correct answer Air entrainment admixtures The fly ash which is used as SCM has the specific gravity ___________________. - correct answer 1.9 - 2.8 The leveling operation that removes lumps and hollows and provides a true and uniform concrete surface is called ______________________. - correct answer Screeding If the quantity of concrete is less than _____________ cubic yards, the compliance test reports are not required. - correct answer 50 Which type of Portland cement is used when early strength is expected? - correct answer Type ||| Which of the following factor influence the positioning of the joints in a slab on grade? - correct answer ALL OF THESE -Sub grade conditions -Finishing requirements -Temperature Which of the following is NOT a property of concrete? - correct answer High tensile strength The concrete work is done in freezing zones, it gets cured by ______________. - correct answer Steam