Materials for Civil and Construction Engineers (4th Edition)
4th Edition
ISBN: 9780134320533
Author: Michael S. Mamlouk, John P. Zaniewski
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 7, Problem 7.38QP
To evaluate the effect of a certain admixture on the flexure strength of concrete, two mixes were prepared, one without admixture and one with admixture. Three beams were prepared of each mix. All the beams had a cross section of 0.15 m by 0.15 m and a span of 0.45 m. The third-point loading flexure strength test was performed on each beam after 7 days of curing. The loads at failure of the beams without admixture were 32.8, 34.5, and 31.7 kN, while the loads at failure of beams with admixture were 39.4, 35.6, and 35.0 kN. Determine:
- a. The modulus of rupture of each beam in MPa.
- b. The average moduli of rupture of the beams without and with admixture.
- c. The percent of increase of the average modulus of rupture due to adding the admixture.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
To evaluate the effect of a certain admixture on the flexure strength of concrete, two mixes were prepared, one without admixture and one with admixture. Three beams were prepared of each mix. All the beams had a cross section of 0.15 m by 0.15 m and a span of 0.45 m. The third-point loadingflexure strength test was performed on each beam after 7 days of curing. The loads at failure of the beams without admixture were 32.8, 34.5, and 31.7 kN, while the loads at failure of beams with admixture were 39.4, 35.6, and 35.0 kN. Determine:a. The modulus of rupture of each beam in MPa.b. The average moduli of rupture of the beams without and with admixture.c. The percent of increase of the average modulus of rupture due to adding the admixture.
To evaluate the effect of a certain admixture on the flexure strength of concrete, two mixes were prepared, one without admixture and one with admixture.
Three beams were prepared of each mix. All the beams had a cross sectionof 0.15 m by 0.15 m and a span of 0.45 m. The third-point loading flexurestrength test was performed on each beam after 7 days of curing. The loads atfailure of the beams without admixture were 32.8, 34.5, and 31.7 kN, whilethe loads at failure of beams with admixture were 39.4, 35.6, and 35.0 kN.Determine:a. The modulus of rupture of each beam in MPa.b. The average moduli of rupture of the beams without and with admixture.c. The percent of increase of the average modulus of rupture due to addingthe admixture.
To evaluate the effect of a certain admixture on the flexure strength of concrete, two mixes were prepared, one without admixture and one with admixture. Three beams were prepared of each mix. All the beams had a cross section of 100 mm * 100 mm and a span of 300 mm. A center-point loading flexure strength test was performed on each beam after 7 days of curing.The loads at failure of the beams without admixture were 26.89, 22.56, and26.40 kN, while the loads at failure of beams with admixture were 32.47,32.49, and 31.06. Determine:a. The modulus of rupture of each beam in GPa.b. The average moduli of rupture of the beams without and with admixture.c. The percent of increase of the average modulus of rupture due to addingthe admixture.
Chapter 7 Solutions
Materials for Civil and Construction Engineers (4th Edition)
Ch. 7 - The design engineer specifies a concrete strength...Ch. 7 - A project specifies a concrete strength of 24.1...Ch. 7 - A project specifies a concrete strength of at...Ch. 7 - What is your recommendation for the maximum size...Ch. 7 - A concrete mix with a 3-in. slump, w/c ratio of...Ch. 7 - Prob. 7.6QPCh. 7 - You are working on a concrete mix design that...Ch. 7 - Design the concrete mix according to the following...Ch. 7 - Design the concrete mix according to the following...Ch. 7 - The design of a concrete mix requires 1173 kg/m3...
Ch. 7 - Prob. 7.11QPCh. 7 - Prob. 7.12QPCh. 7 - Students in the materials lab mixed concrete with...Ch. 7 - Students in the materials lab mixed concrete with...Ch. 7 - Why is it necessary to measure the air content of...Ch. 7 - What do we mean by curing concrete? What will...Ch. 7 - Discuss five different methods of concrete curing.Ch. 7 - Draw a graph showing the typical relation between...Ch. 7 - Why is extra water harmful to fresh concrete, but...Ch. 7 - Discuss the change in volume of concrete at early...Ch. 7 - Discuss the creep response of concrete structures....Ch. 7 - Prob. 7.22QPCh. 7 - On one graph, draw a sketch showing the typical...Ch. 7 - Using Figure 7.34, a. Determine the ultimate...Ch. 7 - Three concrete mixes with the same ingredients,...Ch. 7 - Three concrete mixes with the same ingredients,...Ch. 7 - Three 100 mm 200 mm concrete cylinders with water...Ch. 7 - Students in the materials class prepared three 4 ...Ch. 7 - Three 150 mm 300 mm concrete cylinders with water...Ch. 7 - Three 6 in. 12 in. concrete cylinders with water...Ch. 7 - A normal-weight concrete has an average...Ch. 7 - Discuss the significance of the compressive...Ch. 7 - What is the standard size of PCC specimens to be...Ch. 7 - Prob. 7.34QPCh. 7 - What is the purpose of performing the flexure test...Ch. 7 - What are the advantages of using a third-point...Ch. 7 - Consider a standard flexural strength specimen of...Ch. 7 - To evaluate the effect of a certain admixture on...Ch. 7 - To evaluate the effect of a certain admixture on...Ch. 7 - Prob. 7.40QPCh. 7 - Prob. 7.41QPCh. 7 - A normal-weight concrete has an average...Ch. 7 - Three batches of concrete were prepared using the...Ch. 7 - Three batches of concrete were prepared using the...Ch. 7 - Prob. 7.45QPCh. 7 - Prob. 7.46QPCh. 7 - Discuss two nondestructive tests to be performed...Ch. 7 - Discuss the concept of concrete maturity meters.Ch. 7 - Discuss four alternatives that increase the use...Ch. 7 - What is self-consolidating concrete? How are its...Ch. 7 - Prob. 7.51QPCh. 7 - Two 6 in. 12 in. concrete cylinders with randomly...Ch. 7 - Discuss the concept of high-performance concrete....Ch. 7 - Comparing PCC with mild steel, answer the...Ch. 7 - Prob. 7.55QP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.Similar questions
- To evaluate the effect of a certain admixture on the flexure strength of concrete, two mixes were prepared, one without admixture and one with admixture.Three beams were prepared of each mix. All the beams had a cross section of 4 in. * 4 in. and a span of 12 in. The third-point loading flexure strength test was performed on each beam after 7 days of curing. The loads at failure of the beams without admixture were 6044, 5071, and 5934 lb, while the loads at failure of beams with admixture were 7299, 7305, and 6983. Determine:a. The modulus of rupture of each beam in psi.b. The average moduli of rupture of the beams without and with admixture.c. The percent of increase of the average modulus of rupture due to adding the admixture.arrow_forwardA concrete cylinder of diameter 150mm and length 300mm when subjected to an axial compressive load of 240KN resulted in an increase of diameter by 0.127mm and a decrease in length of 0.28mm.compute the values 1.poison ratio 2.modulus elasticityarrow_forwardIf you knew that the cubic compressive strength of a certain type of concrete is 35 MPa, then calculate the resulting load during the examination, the maximum force applied by the test device)? 1- Fission tensile test 2- Fault modulus test 3- Compressive test for cylinderarrow_forward
- answer very fastarrow_forwardA project specifies a concrete strength of at least 20.7 MPa. Materials engineers will design the mix for a strength higher than that. Calculate the required average compressive strength of the mix design if the standard deviation is s = 2.4 MPa. Estimate the modulus of elasticity of the concrete at the required average compressive strength (the calculated strength, not the given strength).arrow_forwardQ3: B: Design the concrete mix according to the following conditions: Design Environment Building frame Required design strength = 27.6 MPa Minimum dimension = 150 mm Minimum space between rebar = 40 mm Minimum cover over rebar = 40 mm Statistical data indicate a standard deviation of compressive strength of 2.1 MPa is expected (more than 30 samples). Only air entrainer is allowed. Available Materials Air entrainer: Manufacture specification 6.3 ml/1% air/100 kg cement. Coarse aggregate: 19 mm nominal maximum size, river gravel (rounded) Bulk oven-dry specific gravity = 2.55, absorption = 3.6, Oven-dry rodded density = 1761 kg/m3 %3D Moisture content = 2.5, Fine aggregate: Natural sand Bulk oven-dry specific gravity 2.659, absorption=0.5, Moisture content = 2, Fineness modulus = 2.47arrow_forward
- Calculate the modulus of elasticity Ec of lightweight concrete that has a unit weight of 110 pcf and compare it to the modulus of elasticity Ec of a normal weight concrete. Both concretes have compressive strengths (f’c) of 4000 psi. Express the solutions in psi units. Please also explain why the values are different.arrow_forwardComparing PCC with mild steel, answer the following questions:a. Which one is stronger?b. Which one has a higher modulus or stiffness?c. Which one is more brittle?d. What is the range of compressive strength for a typical PCC?e. What is the compressive strength for a high-strength concrete?f. What would be a reasonable range for PCC modulus?arrow_forward! Three 150 mm x 300 mm concrete cylinders with randomly oriented steel fiber contents of 0, 2, and 3% by weight, respectively. After curing for 28 days, the specimens were subjected to increments of compressive loads until fail- ure. The load versus deformation results were as shown in Table P11.14. TABLE P11.14 Specimen No. Fiber Content (%) 1 2 3 2 Deformation (mm) Load (kN) 0.31 565 565 565 0.61 716 (failure) 756 792 0.91 641 756 1.22 440 690 1.52 378 641 1.83 351 (failure) 605 (failure) Assuming that the gauge length is the whole specimen height, determine the following: a. The compressive stresses and strains for each specimen at each load increment. b. Plot stresses versus strains for all specimens on one graph. c. The modulus of elasticity for each specimen. d. The ultimate strength for each specimen. e. The strain at failure for each specimen. f. Toughness. Curves may be approximated with a series of straight lines. g. Comment on the effects of increasing the fiber content on…arrow_forward
- Concrete is required for a column that will be Severe Exposure to freezing and thawing. The cross section of the column is 300 × 300 mm. The smallest spacing between reinforcing steel is 40 mm. The specified compressive strength of concrete at 28 days is 40 MPa with a slump of 25 to 50 mm. The properties of materials are as follows: (a) Cement used is type I Portland cement with a specific gravity of 3.10. (b) The available coarse aggregate has a maximum size of 23 mm, a dry-rodded unit weight of 1800 kg/m3, a bulk specific gravity (SSD) of 2.68, absorption capacity of 0.65%, and moisture content (SSD) of 0.27%. (c) The fine aggregate has a bulk specific gravity (SSD) of 2.75, absorption capacity of 1.5%, a moisture content (SSD) of 2.5%, and a fineness modulus of 2.7,The aggregates conform to the ASTM C33-84 requirements for grading.arrow_forwardDesign the concrete mix according to the following conditions:Design EnvironmentPavement slab, subjected to freezingRequired design strength = 21 MPaSlab thickness = 300 mmStatistical data indicate a standard deviation of compressive strength of1.7 MPa is expected (more than 30 samples).Only air entrainer is allowed.Available MaterialsAir entrainer: Manufacture specification is 9.5 mL/1% air/100 kgcement.Coarse aggregate: 2 in. nominal maximum size, crushed stoneBulk oven-dry specific gravity = 2.573, absorption = 2.8,Oven-dry rodded density = 1922 kg/m3Moisture content = 1,Fine aggregate: Natural sandBulk oven-dry specific gravity = 2.540, absorption = 3.4,Moisture content = 4.5,Fineness modulus = 2.68arrow_forwardThe third-point loading flexure strength test was performed on a IVI ... concrete beam having a cross section of 0.15 m by 0.15 m and a span of 0.45 m. If the load at failure was 35.7 kN, calculate the flexure strength of the concrete. This normal-weight concrete has an average compressive strength of 20 MPa. What is the estimated flexure strength (hints: use the ACI equation)?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Structural Analysis (10th Edition)Civil EngineeringISBN:9780134610672Author:Russell C. HibbelerPublisher:PEARSON
Principles 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 Education
Traffic and Highway EngineeringCivil EngineeringISBN:9781305156241Author:Garber, Nicholas J.Publisher:Cengage Learning
Structural Analysis (10th Edition)
Civil Engineering
ISBN:9780134610672
Author:Russell C. Hibbeler
Publisher:PEARSON
Principles of Foundation Engineering (MindTap Cou...
Civil Engineering
ISBN:9781337705028
Author:Braja M. Das, Nagaratnam Sivakugan
Publisher:Cengage Learning
Fundamentals of Structural Analysis
Civil Engineering
ISBN:9780073398006
Author:Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:McGraw-Hill Education
Traffic and Highway Engineering
Civil Engineering
ISBN:9781305156241
Author:Garber, Nicholas J.
Publisher:Cengage Learning
Concrete Slab Calculations 006; Author: Jerry Howard;https://www.youtube.com/watch?v=R19jILyBxio;License: Standard Youtube License