1、An ACI Technical Publication SYMPOSIUM VOLUMESP-307Shrinkage Compensating Concrete Past, Present, and FutureEditor:Chris RamseyerShrinkage Compensating Concrete Past, Present, and FutureSP-307Editor:Chris Ramseyer Discussion is welcomed for all materials published in this issue and will appear ten m
2、onths from this journals date if the discussion is received within four months of the papers print publication. Discussion of material received after specified dates will be considered individually for publication or private response. ACI Standards published in ACI Journals for public comment have d
3、iscussion due dates printed with the Standard.The Institute is not responsible for the statements or opinions expressed in its publications. Institute publications are not able to, nor intended to, supplant individual training, responsibility, or judgment of the user, or the supplier, of the informa
4、tion presented.The papers in this volume have been reviewed under Institute publication procedures by individuals expert in the subject areas of the papers.Copyright 2016AMERICAN CONCRETE INSTITUTE38800 Country Club Dr.Farmington Hills, Michigan 48331All rights reserved, including rights of reproduc
5、tion and use in any form or by any means, including the making of copies by any photo process, or by any electronic or mechanical device, printed or written or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device, unless permission in writing
6、is obtained from the copyright proprietors.Printed in the United States of AmericaEditorial production: Gail TatumISBN-13: 978-1-942727-70-5First printing, March 2016PrefaceWith the exception of #9, these Papers were presented at: ACI National Convention, Fall 2012 Toronto, Canada In the Technical S
7、ession Shrinkage Compensating Concrete Past, Present, and Future Part 1 and Part 2 This Publication is Dedicated to Edward K. Rice Ed Rice has been involved in Shrinkage Compensating Concrete from its inception. As cofounder and President of T.Y. Lin and Associates from 1952 through 1970 EdRice prom
8、oted the novel use of concrete and concrete systems. As early as 1956 T.Y. Lin and Ed Rice provided the necessary funding for fundamental research by Alex Klein on expansive cements. This research led to the development of the Chemically Prestressed Concrete (CPC) co that was primarily in the pipe a
9、nd roof slab business. In 1965 under Ed Rices direction as Chairman of CPC, Ed licensed Kaiser to run the first full scale burn at their Cushenberry cement plant and commercially produce the first shrinkage compensating concrete clinker in the world. In the fifty years since the first production run
10、 of shrinkage compensating cement Ed Rice has consistently worked to advance concrete cement technology. He holds 22 US patents in the field of concrete and building technology. For the last forty years Ed Rice has led CTS Cement Manufacturing Co., the largest producer of shrinkage compensating ceme
11、nt in North America. Often Ed Rice worked behind the scenes helping to promote shrinkage compensating concrete and the work of younger engineers. Ed Rice has been a consistent and steady advocate for both increased research on the behavior of shrinkage compensating cements; and increased use of shri
12、nkage compensating concrete to produce stable and durable concrete structures.TABLE OF CONTENTSSP-3071History of Shrinkage Compensating Cement .1Author: Edward K. RiceSP-3072A Look Back at 1974 Type K Cements .21Author: George C. HoffSP-3073Behavior of Type K Shrinkage Compensating Concrete Under Va
13、rious Forms of Mechanical Restraint 41Authors: Chris Ramseyer and Seth RoswurmSP-3074Dimensional Stability of Concrete Slabs on Ground .53Authors: Shideh Shadravan, Thomas H.K. Kang, and Chris RamseyerSP-3075Extending Joint Spacing with Shrinkage Compensating Concrete 65Authors: Ed McLean and Seth R
14、oswurmSP-3076600 Crack Free Bridges Using Shrinkage Compensating Concrete 85Authors: Ed McLean, Chris Ramseyer, and Seth Roswurm SP-3077Behavior of Shrinkage Compensating Concrete in an Unrestrained and Restrained Environment 101Authors: Chris Ramseyer and Kyle Renevier SP-3078Evaluation of the Robu
15、stness of Shrinkage Compensating Concrete Repair Concretes Prepared with Expansive Components .113Authors: Chris Ramseyer and Seth Roswurm SP-3079Experiences on the Use of Expansive Component Type G in Mexico 123Authors: Kyle Renevier, Lawrence Valentine, and Chris Ramseyer SP-3071 1.1 History of Sh
16、rinkage Compensating Cement Edward K. Rice Synopsis: This short work details the history of Type K shrinkage compensating cement. Keywords: Development, history, Klein, shrinkage compensating cement, type K, SCC, Concrete shrinkage Edward K. Rice 1.2 Author Biography: Edward K. Rice, P.E., FACI, FAS
17、CE, is the founder and Chairman of CTS Cement Manufacturing Co, a leading manufacturer of specialty cements. He holds 22 patents in concrte and building technology. He is a member of the Post-Tensioning Institute Hall Of Fame, ASTM Honorary Member Committee C1, UC Berkeley Distinguished Engineering
18、Alumnus and UCLA Lifetime Contributing Member History of Shrinkage Compensating Cement 1.3 INVENTION AND EARLY DEVELOPMENT There are three primary types of expansive cement in ASTM C845: Type K, Type M, and Type S. ACI 223 now also recognizes Type G. My talk will only discuss the history of Type K a
19、s I know it. Type K was developed under the supervision of Alexander Klein at the University of California, Berkeley. Alexander Klein joined the Berkeley research team in 1934 and worked on cement for the Hoover Dam. Figure 1: Alexander Klein (1902 - 1970) In the early 1950s, Klein began work on exp
20、ansive cements. Others had developed expansive cements, but Kleins expansive cement was unique in that the expansion was controllable and the expansion stopped in an appropriate time. Many other expansive cements expanded to destruction. Kleins expansive cement was fundamentally based on the formati
21、on of C4A3S “Ettringite” crystals during the hydration of the cement. Because he was responsible for some of the earliest developments in this field, C4A3S is often referred to as the Klein compound. Two examples of ettringite crystal growth appear in Figure 2 and Figure 3. Figure 2: Ettringite Crys
22、tal Growth Edward K. Rice 1.4 Figure 3: Nucleation of Ettringite (also called Bescher balls) In the early development of Kleins expansive cement, many thought it was the work of a madman to knowingly create a mechanism for ettringite production. This was based on the idea that the crystal would tend
23、 to expand without bound, thus compromising the material. However, Kleins ettringite crystals form quickly and the expansion terminates on hydration of C4A3S; the expansion of other types of ettringite crystals may not terminate in other systems. In the late 1950s, the Berkeley lab did quite a bit o
24、f work on the pre- and post-tensioning of concrete and its limitations. It was thought that one could use Kleins expansive cement to chemically pre-stress (Chem Stress) concrete (particularly on thin shells and pressure pipe). Both shells and pressure pipes were successfully constructed in the Berke
25、ley lab, as illustrated in Figure 4 and Figure 5. Figure 4: Chemical Pre-Stressing of a Thin Concrete Shell at Berkeley Lab History of Shrinkage Compensating Cement 1.5 Figure 5: Chemical Pre-Stressing of a Concrete Pressure Pipe at Berkeley Lab CONCEPTS AND FUNCTION The function of Shrinkage Compen
26、sating Concrete (also called SCC) is quite simple. When the concrete is mixed, ettringite crystals begin to form and cause a slight expansion in the concrete. Regular reinforcing steel provides the necessary restraint to place the concrete in compression. This compression in the concrete is necessar
27、ily accompanied by tension in the steel during the expansive phase of the concrete. As the concrete dries out, it shrinks. In the case of SCC, the concrete shrinkage is ideally the same as the expansion, and the concrete ultimately returns to its as-cast length. This process is illustrated in Figure
28、 12. The maximum expansion is roughly equivalent to the change in length that would be caused by a 100F increase in temperature. Figure 6: Shrinkage Compensation Compared to Conventional PCC Edward K. Rice 1.6 With the increased use of SCC over time, appropriate ASTM specifications have been develop
29、ed for its use and testing. The ASTM specification for testing shrinkage or expansion of Portland cement mortar or concrete is ASTM C157. In this test, length changes are measured at specified times on a bar 10” long. In order to accommodate testing of SCC concrete, the C157 bar is modified to provi
30、de the necessary restraint. This longitudinal restraint is provided by a restraining steel rod placed in the center of the bar. The restrained expansion bar test for concrete is ASTM C878, which utilizes a 3”x3”x10” bar. The steel area in the 1/8” diameter restraining rod is equal to 0.15% of the co
31、ncrete area; this percentage is equal to the code minimum steel requirement for all concrete in the 1960s when this test was developed. The test for mortar is ASTM C806, which utilizes a 2”x2” bar. The size of the restraining rod in this specimen is of ” diameter in order to achieve a mortar expansi
32、on similar to that of the C878 concrete test. While the C878 test is used to characterize the expansion of a concrete, the C806 test is used to determine the expected expansion from a particular cement. These restrained bar test were developed by Edward H. Rubin, FACI, and as a result the expansion
33、bars are often referred to as Ruben bars. In addition to the specifications for testing SCC, there is also a standard specification for expansive cement. Properties and performance of expansive cement are dictated by ASTM C845; this standard is similar to ASTM C150 for Portland cement, except that C
34、845 includes an expansion-based performance requirement. The C845 specification requires a mortar bar expansion of 0.04% to 0.1% at 7 days and the 28-day expansion is not allowed to exceed 115% of the 7-day expansion. In developing these expansion limits for shrinkage compensating cement, it was tho
35、ught that limiting the 28-day expansion would allow direct substitution of SCC for PCC in any structure without making any design changes. Using the ASTM specification, a great number of SCC structures have been constructed without making any special provisions for the expansion of the SCC Type K ex
36、pansive cements are generally made by manufacturing an expansive Klein clinker containing C4A3S and either inter-grinding the clinker with Portland cement and gypsum, or mixing ground Klein clinker with Portland cement and gypsum. The combination of ground Klein clinker and gypsum is often referred
37、to as component. The advantage of the component system is that expansion may be adjusted to meet any specific need. The component system also has a major advantage over the inter-ground system in shipping cost, since local Portland cement can be used and only about 15% of the required mix must be sh
38、ipped. IMPLEMENTATION Ultimately, the potential market for chemically pre-stressed concrete was too small to warrant widespread full-scale production in a cement plant. However, a six-story apartment building was later constructed with chemically pre-stressed 2” thick concrete walls and 4.5” thick f
39、loors. Fabrication and assembly of this building are illustrated in Figure 6 through Figure 9. Figure 7: Fabrication of Chemically Pre-Stressed Apartment Building History of Shrinkage Compensating Cement 1.7 Figure 8: Modular Construction of Apartment Building using chemically Pre-Stressing Figure 9
40、: Construction of Apartment Building Edward K. Rice 1.8 Figure 10: Fully Constructed Chemically Pre-Stressed Apartment Building During the 1950s, a considerable number of post-tensioned lift slab structures were constructed. As the size of buildings increased, drying shrinkage became a serious struc
41、tural problem. As the drying shrinkage took place, the floor and roof slabs became shorter and caused significant distress at the shear walls and stair connections. Slip joints were considered as a potential solution, but were not practical. By adding Kleins compound to Portland cement, however, one
42、 could compensate for drying shrinkage and the slab stayed the same size as cast. This is referred to as Shrinkage Compensating Cement Concrete, since the amount of shrinkage was balanced or compensated for by the expansion of the Klein compound. The benefit of such a process is readily apparent, an
43、d the potential market for making a Klein (Type K) Shrinkage Compensating Cement was large enough to justify commercial production in a full-scale cement plant. A patent holding partnership named Chemically Prestressed Concrete (CPC) was formed in 1961 to develop and license the Klein cement technol
44、ogy. Klein applied for patents on SCC in 1961 and Kaiser Cement and Gypsum Company of Oakland, California, became the first cement company licensed to make Klein SCC in 1962. The CPC partnership was incorporated in 1963 and three patents were issued over the next several years (one in 1964, one in 1
45、966, and one in 1967). In 1962, Caltrans was keenly interested in finding a solution to shrinkage in concrete pavement, and they let a contract to pour two one-mile sections of pavement. This was a large enough order to warrant production, and the first Type K clinker was made January 4, 1963, at th
46、e Kaiser plant in Cushionberry, California. The first one-mile section of pavement was placed on Highway 14 near Lancaster, CA; the second was placed near Lodi, CA. Paving was done using a two-lane wide slip form paver, and expansion joints were placed every 440 feet. After two years, drying shrinka
47、ge cracks were measured and found to be spaced approximately double the distance expected with PCC, and these pavements (shown in Figure 11) are still in service today. History of Shrinkage Compensating Cement 1.9 Figure 11: One Mile of SCC Pavement in 1963 near Lancaster, CA (Caltrans) Several othe
48、r cement companies including Medusa, TXI, Penn Dixie, and Southwest Portland subsequently obtained licenses to manufacture Type K. These additional licensees provided complete geographical coverage, making Type K available throughout the US. The Dyckerhoff Cement Company in Germany was also a licens
49、ee. In 1970, the Uniform Building Code approved the use of Type K cement as a satisfactory substitute for Portland Type I or Type II cement in structural concrete. The ACI Klein Symposium on Expansive Cement Concrete, which was held at the Fall ACI convention in November 1973, was published by ACI as a special publication (SP38). This publication contains 20 papers covering R&D and application of SCC in the US, Japan, and the USSR. The ACI Cedric Wilson Symposium on Expansive Concrete, which was held at eh fall ACI convention in 1977, was also published as a sp
