Concept explainers
Students in the materials lab mixed concrete with the following ingredients: 9.7 kg of cement, 18.1 kg of sand, 28.2 kg of gravel, and 6.5 kg of water. The sand has a moisture content of 3.1% and an absorption of 4.2%. The gravel has a moisture content of 3.4% and an absorption of 4.4%. Since water absorbed in the aggregate does not react with the cement or improve the workability of the plastic concrete, what is the water-cement ratio of this mix according to the American Concrete Institute’s weight mix design method? If a water–cement ratio of 0.5 is required using the same materials and ingredients but different amount of mixing water, what is the weight of the mixing water to use?
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
Materials for Civil and Construction Engineers (2nd Edition)
Additional Engineering Textbook Solutions
Elementary Surveying (14th Edition)
Structural Analysis (10th Edition)
Structural Steel Design (6th Edition)
Elementary Surveying: An Introduction To Geomatics (15th Edition)
Foundation Design: Principles and Practices (3rd Edition)
Basics Of Engineering Economy
- If the target slump of concrete is 30 mm, the maximum nominal size of the coarse aggregate is 25 mm, and the smallest nominal size is 9.5 mm, how much water is needed in the ordinary concrete mix? If the target slump of concrete is 85 mm, the maximum nominal size of the coarse aggregate is 37.5 mm, and the smallest nominal size is 9.5 mm, how much water is needed in the ordinary concrete mix? If the compressive strength of concrete at 28 days is 38 MPa and the concrete is non-air entrained, what is the water-cement ratio of the concrete mix? If the required compressive strength of air entrained concrete is 26 MPa, what is the water-cement ratio of the concrete mix? The required Class D concrete is 5 cubic ft. What is the volume of sand in the 5 cubic ft. concrete mix. Mixing water is one half of the amount of cement powder.arrow_forwardThe volume of concrete required for a certain project is 20m^3. The density of concrete is 2400kg/m^3. Concrete is composed of fine and coarse aggregates, water, and cementitious materials: cement and fly ash. The ratio of fine and coarse aggregates is 2:1. Water-to-cement ratio is 0.40. Percentage of the fly ash to the total cementitious material is 0.30. Total aggregate-to-cement ratio is 5:1. Density of fine aggregates is 2680kg/m^3. Density of coarse aggregate is 2500kg/m^3. Density of water is 1000kg/m^3. Density of cement is 3150kg/m^3. Density of fly ash is 1300kg/m^3. Determine the weight required for each component. All ratios use weights. Round off your answers to the nearest tenth of a kilogram. Have one significant figure after the decimal point. Find: Weight of Fine Aggregates: Weight of Coarse Aggregates: Weight of Water: Weight of Cement: Weight of Fly Ash:arrow_forwardRead the question carefully and give me right solution according to the question. If you don't know the solution please leave it but don't give me wrong solution. Dry weight of coarse aggregate, fine aggregate and water for 1 m3 of one type of concrete requires 1100 kg, 680 kg and 175 liters, respectively. From laboratory test for, it is determined that absorption content of coarse and fine aggregates is 0.5% and 1.25%, respectively. Meanwhile, moisture content of coarse and fine aggregate is 0.75% and 1.0%, respectively. Determine weight of coarse aggregate, fine aggregate and water for one batch with volume of mixer of 800 liter.arrow_forward
- Q. Using the British methods, design a concrete mix to bear an average compressive strength of 35 MPa at 28 days, to cast a room slab with the following dimensions (5 width x 4 length x 0.2 depth m) and 200 mm space distance of reinforcement. Consider the following properties: o Cement used is type I Portland cement ® Required slump = 30 — 60 mm o Coarse aggregate: ® Crushed rocks * Maximum size of 40 mm, e The fine aggregate: * Crushed rocks = Falls in zone 3 o Assume zone A for figure 1 o AssumeK = 1.64arrow_forwardThe design of a concrete mix requires 1173 kg/m3of gravel in dry condition,582 kg/m3of sand in dry condition, and 157 kg/m3of free water. The gravelavailable at the job site has a moisture content of 0.8% and absorption of1.5%, and the available sand has a moisture content of 1.1% and absorptionof 1.3%. What are the masses of gravel, sand, and water per cubic meter thatshould be used at the job site?arrow_forwardYou are working on a concrete mix design that requires each cubic yard of concrete to have a 0.43 water–cement ratio, 1232 kg/m3 of dry gravel, 145 kg/m3 of water, and 4% air content. The available gravel has a specific gravity of Ggravel = 2.60, a moisture content of 2.3%, and absorption of 4.5%. The available sand has a specific gravity of Gsand = 2.40, a moisture content of 2.2%, and absorption of 1.7%. Air entrainer is to be included using the manufacturers specification of 6.3 mL/1% air/100 kg cement. For each cubic meter of concrete needed on the job, calculate the weight of cement, moist gravel, moist sand, and water that should be added to the batch. Summarize and total the mix design when finished.arrow_forward
- Students in the materials class prepared three mortar mixes with water to cement ratios of 0.50, 0.55, and 0.60. Three 50-mm mortar cubes were pre- pared for each mix. The cubes were cured for 7 days and then tested for com- pressive strength. The test results were as shown in Table P6.16.Determine the following: a. The compressive strength of each cube. b. The average compressive strength for each mix. c. Plot the average compressive strength versus w/c ratios for all mixes. d. Comment on the effect of increasing w/c ratio on the compressive strength of the cubes.arrow_forwardThe results of a laboratory experiment to evaluate the effects of a plasticizer are shown.a. Calculate the water/cement in each of the three cases. b. Choose an appropriate case that - by using water reducer, how can we increase the compressive strength of concrete without changing workability? (Refer to the appropriate case in the table) c. Choose an appropriate case that - by using a water reducer, how can we improve workability without changingthe compressive strength? (Refer to the appropriate case in the table)d. Choose an appropriate case that - by using water reducer, how can we reduce cost without changing workability or strength? (Refer to the appropriate case in the table)arrow_forwardYou are working on a concrete mix design that requires each cubic meter of concreteto have 0.40 water–cement ratio, 1165 kg/m3 of dry gravel, 4% air content, and 335kg/m3 of cement (Specific Gravity = 3.15). The available gravel has a specific gravityof (S.G) gravel = 2.7, a moisture content of 1.6%, and absorption of 2.4%. The availablesand has a specific gravity of (S.G) sand = 2.5, a moisture content of 4.8%, andabsorption of 1.5%.For each cubic meter of concrete needed on the job, calculate the mass of cement,moist gravel, moist sand, and water that should be added to the batch. Summarizethe total the mix design in a table.arrow_forward
- What are the common minerals found in various kinds of aggregates used in concrete?arrow_forwardThree batches of concrete were prepared using the same materials and ingredients, except that they have water–cement ratios of 0.50, 0.55, and 0.60,respectively. The following tests were performed on specimens made of thethree batches:■ Compressive strength test on 100 mm * 200 mm cylinders■ Center-point flexure test on 100 mm * 100 mm * 300 mm beams■ Split tension test on 150 mm * 300 mm cylindersThree replicates were tested for each test. Table P7.38 shows the average failure loads for the three replicates of each case.It is required to do the following:a. Complete Table P7.38b. Using an Excel sheet, plot the relationships between water–cement ratioand compressive strength, modulus of rupture, and tensile strength on thesame graph. Label all axes and curves.c. Comment on the effect of water–cement ratio on the compressive strength,modulus of rupture, and tensile strength.arrow_forwardWhat are the functions of aggregate used in portland cement concrete?arrow_forward
- Structural Analysis (10th Edition)Civil EngineeringISBN:9780134610672Author:Russell C. HibbelerPublisher:PEARSONPrinciples of Foundation Engineering (MindTap Cou...Civil EngineeringISBN:9781337705028Author:Braja M. Das, Nagaratnam SivakuganPublisher:Cengage Learning
- Fundamentals of Structural AnalysisCivil EngineeringISBN:9780073398006Author:Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel LanningPublisher:McGraw-Hill EducationTraffic and Highway EngineeringCivil EngineeringISBN:9781305156241Author:Garber, Nicholas J.Publisher:Cengage Learning