Library of Congress Cataloging-in-Publication Data Kett, Irving. Engineered concrete : mix design and test methods / Irving Kett. -- (Concrete technology series) Includes bibliographical references.1'36—dc21 99-39814 CIP This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated.
A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage or retrieval system, without prior permission in writing from the publisher. The consent of CRC Press LLC does not extend to copying for general distribution, for promotion, for creating new works, or for resale.
Specific permission must be obtained in writing from CRC Press LLC for such copying. Direct all inquiries to CRC Press LLC, 2000 N., Boca Raton, Florida 33431. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. Visit the CRC Press Web site at www.com © 2000 by CRC Press LLC No claim to original U.
Government works International Standard Book Number 0-8493-2277-4 Library of Congress Card Number 99-39814 Printed in the United States of America 2 3 4 5 6 7 8 9 0 Printed on acid-free paper DEDICATION With appreciation and love, I dedicate this textbook to my darling wife, Ethel. ©2000 CRC Press LLC CONTENTS SECTION I: INTRODUCTION Introduction Brief Overview of Portland Cement and Concrete Technology Mix Design Procedures SECTION II: TESTS FOR AGGREGATES, PORTLAND CEMENT, AND MORTAR Test Description (ASTM Designation) Rodded Unit Weight of Coarse Aggregates (C 29) Compressive Strength of Hydraulic Cement Mortars (C 109) Specific Gravity and Absorption Tests of Coarse and Fine Aggregates (C 127/128) Resistance to Degradation of Small-Size Coarse Aggregate in the Los Angeles Machine (C 131) Test Method for Sieve Analysis of Fine and Coarse Aggregates (C 136/117) Clay Lumps and Friable Particles in Aggregates (C 142) Test Method for Density of Hydraulic Cement (C 188) Tensile Strength of Hydraulic Cement Mortars (C 190) Test Method for Time of Setting of Hydraulic Cement by the Vicat Needle (C 191) Fineness of Portland and Other Hydraulic Cements by Air Permeability Apparatus (C 204) Sand Equivalent Value of Soils and Fine Aggregate (D 2419) Index of Aggregate Particle Shape and Texture (D 3398) Flat and Elongated Particles in Coarse Aggregate (D 4791) Standard Specifications for Wire Cloth and Sieves for Testing Purposes (E 11) SECTION III: TESTS FOR PORTLAND CEMENT CONCRETE Compressive Strength of Cylindrical Concrete Specimens (C 39) Flexural Strength of Concrete Using Simple Beam with Third-Point Loading (C 78) Unit Weight, Yield, and Air Content of Concrete (C 138) ©2000 CRC Press LLC Slump of Hydraulic Cement Concrete (C 143) Air Content of Freshly Mixed Concrete by the Volumetric Method (C 173) Making and Curing Concrete Test Specimens in the Laboratory (C 192) Air Content of Freshly Mixed Concrete by the Pressure Method (C 231) Bond Strength of Concrete Developed with Reinforcing Steel (C 234) Ball Penetration in Fresh Portland Cement Concrete (C 360) Static Modulus of Elasticity and Poisson’s Ratio of Concrete in Compression (C 469) Splitting Tensile Strength of Cylindrical Concrete Specimens (C 496) Rebound Number of Hardened Concrete by the Swiss Hammer (C 805) Direct Tensile Test of Portland Cement Concrete (No Reference) SECTION IV: APPENDICES A: Measurement Conversion Factors between the S. System and the U. Standard Units B: Laboratory Rules of Safety and Procedures C: Tables of Portland Cement Specifications from ASTM Designation: C 150 D: Concrete Admixtures and Other Cementitious Materials E: Development of ASTM Standards F: Sample Course Outlines for 10-Week and 15-Week Laboratory Sessions G: Bibliography Additional Copies of Laboratory Data Sheets ©2000 CRC Press LLC THE AUTHOR Irving Kett Ph.
has been a professor of civil engineering at California State University, Los Angeles for the past 28 years. Prior to his academic appointment, he spent over 25 years in the practice of engineering, principally in the design and con- struction of highways, bridges, and airports. In addition to his work in the U., including Alaska, Dr. Kett also practiced engineering in Asia and Europe.
As a faculty member in the civil engineering department, Dr. Kett’s area of specialization has been transportation. However, he has been responsible for the concrete laboratory for a number of years. It was while teaching this course for undergraduate civil engineering students and conducting research projects in concrete with graduate students that, over the years, he gradually devel- oped the textbook on concrete laboratory procedures.
During his career as a civil engineer, Dr. Kett published 18 professional articles, based mainly upon his professional experience, and four textbooks. He has been a Fellow in the American Society of Civil Engineers since 1966 and a member of eight professional and honorary engineering societies. He holds four university degrees.
During World War II, Dr. Kett served in the U. Army in the Pacific Theater and later in Korea. As a reservist in the 1960s and 70s, he was sent to Europe on 14 short tours of duty.
Prior to his retirement from the service, he was called back to active duty and sent to the Middle East for 3 years to help supervise the construction of two high-performance airbases. Kett’s civilian career has always been the military commitment since he remained an active reservist in the U. Army Corps of Engineers until his retirement in 1982 with the rank of Colonel. ©2000 CRC Press LLC ACKNOWLEDGMENT I have encountered many fine students over my years of teaching.
Probably one of the most gifted graduate students that I have had the pleasure of having in my class was Michael M. He deserves recognition for his contribution to this book by virtue of his artistic enhancement of the text. ©2000 CRC Press LLC II TESTS FOR AGGREGATES, PORTLAND CEMENT, AND MORTAR ©2000 CRC Press LLC RODDED UNIT WEIGHT OF COARSE AGGREGATES (ASTM Designation: C 29) PURPOSE Determination of the unit weight of coarse aggregates in a compacted condition. This test method is applicable to aggregates not exceeding 15 cm (6 in.) in nominal size.
The unit weight so determined is necessary for the design of a concrete mixture by the absolute value method as explained beginning on pages 12 and 16, depending on the system of measurements. EQUIPMENT AND MATERIALS Balance accurate to 0.1 lb) with a range to at least 25 kg (64 lb) Straight steel tamping rod 16 mm (5/8 in.) diameter and about 60 cm (24 in.) in length with one end rounded in a hemispherical tip Watertight metal bucket having approximately equal height to diameter ratio, but the height should always be between 80 to 150% of the diameter Quantity of oven-dry aggregate sample should be at least 125% of the quantity required to fill the metal pail TEST PROCEDURE 1. Calibrate the metal bucket to determine its volume by determining the net weight of water required to fill it and dividing it by the density of water. For this test procedure, it is sufficiently accurate to accept the density of water at room temperature to be 998 kg/m3 (62.
Rodding the aggregates: Fill the bucket one third full and rod the aggregate layer with 25 strokes of the tamping rod, evenly distributed over the surface. Add another layer of aggregates so that the bucket is approximately two thirds full and repeat the rodding procedure. The third layer of aggregates should fill the pail to overflowing. Again repeat the tamping procedure and strike off the excess with the tamping rod.
Manually try to balance the depressions below the top of the bucket with slight projections above the top. When tamping the first lift, do not permit the rod to penetrate to the bottom of the bucket. However, the subsequent lifts should penetrate to the top of the previous lift. The rodded unit weight is computed in kg/m 3 (lb/ft3) from the net weight of the rodded aggregates in the bucket divided by its volume.
©2000 CRC Press LLC EXPLANATION OF COMPUTATIONS AND DATA SHEET 1. Computations: Calculate the rodded unit weight as follows: MSS = Rodded unit weight of the saturated surface dry aggregate, D kg/m3(lb/ft3) G = Combined mass of the oven-dry aggregate and the bucket, kg(lb) T = Mass of the bucket alone, kg(lbf) V = Volume of the bucket, m3(ft3) A = Percent absorption, determined by ASTM Method: C 127 MSS = (G – T)(1 + A/100)/V D Calculate the rodded unit weight to the nearest 10 kg/m3 (1 lb/ft3). Conduct three tests. Average any two that do not differ by more than 40 kg/m3 (2.
Data sheet: There are no special data sheets for this test. Follow the instructions included in the above Test Procedure. ©2000 CRC Press LLC COMPRESSIVE STRENGTH OF HYDRAULIC CEMENT MORTARS (ASTM Designation: C 109) PURPOSE The following covers only that portion of ASTM Designation: C 109 that is required to determine the compressive strength of 50-mm (2-in.) portland cement mortar cubes. EQUIPMENT AND MATERIALS Two-kg scale accurate to 0.1 gram Six 50 mm (2 in.) cube molds Hard rubber tampers 13 × 25 mm (1/2 × 1 in.) cross section and 12 to 15 cm (5 to 6 in.) in height Rubber gloves Small steel trowels Large spoons Electrically driven mechanical mixer equipped with a paddle and mixing bowl as shown in Figure 3 500 grams of portland cement 1375 grams of Ottawa Sand 242 cc of water TEST PROCEDURE 1.
Place the 242 cc of water in the mixing bowl, add the 500 grams of cement, and mix at a slow speed (140 ± 5 rpm) for 30 seconds. Add the 1375 grams of Ottawa Sand over a 30-second period while continuing to mix at a slow speed. Stop the mixing, change the mixer setting to medium speed (285 ± 5 rpm), and mix for 30 seconds. Stop the mixer and let the mortar stand for 90 sec.
During the first 15 seconds, scrape down into the batch any mortar that may have collected on the sides of the bowl. Cover the bowl for the remainder of the interval. Finish preparing the mortar by mixing for 60 seconds at medium speed. Immediately upon completion of mixing, start molding the specimens by placing a 25 ± mm (1 ± in.) layer of mortar in all of the six cube compartments.
Tamp the mortar layer in each cube compartment with the hard rubber tamper 32 times within about 10 seconds in accordance with Figure 4 in four rounds. Each round to be at right angles to the other and consisting of eight adjacent strokes over the surface of the specimen. Use sufficient tamping ©2000 CRC Press LLC Figure 3 Mixing bowl and paddle from ASTM Designation: C 305.) pressure to ensure uniform filling of the molds. Complete the lift in each mold in turn before moving on to the next one.
Complete the filling of the molds by adding another layer and duplicate the tamping procedure. At this point the mortar should be slightly above the top of the molds. Carefully cut the excess mortar flush with the edge of a steel trowel. Place the completed mortar cubes in a moist closet, protected from dripping water for 20 to 24 hours after which the cubes are to be stripped from the molds.
Insert the mortar cubes in a saturated lime water bath until ready for testing. The lime water should be changed periodically to keep the water clean.