%PDF-1.7 %���� ACI 301-10 specifies a maximum temperature of 95°F. ACI GRADE 1 FIELD TESTING CERTIFICATION PRACTICE TEST . I'm not sure where the rule is located in ACI 318-14. h�bbd``b`f�@�i#�`���� B�$D�� �[�&�X'@�w ��HpG�� �/��� !�$�@:��dq&F�s u�4$�3�y` ] Section Size, minimum dimension <12” 12 to 36” Line Air Temperature Minimum concrete temperature as placed and maintained 1 - 55°F 50°F Minimum concrete temperature as mixed for the indicated air temperature* 2 Above 30oF 60°F 55°F 3 0 to 30oF 65°F 60°F 4 Below 0oF 70°F 65°F 5 Maximum allowable gradual temperature drop in the first 24 hours after end of … ACI 306R-10 Table 5.1, Temperature of Concrete includes recommended concrete temperatures by the air temperature range and by the minimum dimensions of the concrete section size. f min = 0.0015. Concrete international MAY 2014 47 below 32°F [0°C]).5 However, given the recommendations in ACI 306R-10,4 ACI 306.1-90,3 and ACI 301-10,2 the minimum concrete temperature as placed must be at least 40°F (5°C). endstream endobj startxref If you have a 3ft thick section, then you can just look at top 1ft and bottom 1ft individually for minimum T & S steel. 4. from center of nearest exterior surface 3) Shaded location to monitor ambient temperature • Monitor temperatures hourly • Compare temperatures with limits 17 h�b```a``�"W&11 �+P����i�B�CrOH���.���Ix���}���z*�@��+&O'%.�u�^�;G0��n�2�F� �aY����-R��ܻ�����t�W Note 2: For Lines 2-4, maximum temperature is minimum temperature in the table plus 15 °F (9 °C). 87 0 obj <>/Filter/FlateDecode/ID[<8599594788DAD647BF92DBB45F3C42EE><474F1AD6159296469D74E6DF036507F6>]/Index[63 46]/Info 62 0 R/Length 108/Prev 496811/Root 64 0 R/Size 109/Type/XRef/W[1 2 1]>>stream "u�1� dk�L�&�J�"/G�x�'0���A*. ��z�z>��OQ�� ���>#���������F��e�����٦�m���? ACI 306R-16: Guide to Cold Weather Concreting Author: ACI Committee 306 Subject: This document guides specifiers, contractors, and concrete producers through the selection processes that identify methods for cold weather concreting. endstream endobj 67 0 obj <>stream endstream endobj 1584 0 obj <>>>/MarkInfo<>/Metadata 112 0 R/Names 1598 0 R/Outlines 453 0 R/PageLabels 1578 0 R/Pages 1581 0 R/StructTreeRoot 490 0 R/Type/Catalog/ViewerPreferences<>>> endobj 1585 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageC]/XObject<>>>/Rotate 0/StructParents 97/Tabs/S/Thumb 109 0 R/TrimBox[0.0 0.0 612.0 792.0]/Type/Page>> endobj 1586 0 obj <>stream -Concrete temperature (2.3) The concrete temperature at the time of placement should not be lower than the values given in Table 3.1, also the concrete temperature should be maintained at the recommended placement temperature for the required protection period. The American Concrete Institute (ACI) specifies in ACI 306R-16 Guide to Cold Weather Concreting recommended concrete temperatures based on the air … The protection period is defined as being between one and four days for concrete with accelerators mixed in (Table 7.1 of ACI 306). %%EOF In case of an isolated footing with a depth greater … The minimum amount and spacing of reinforcement to be used in structural floors, roof slabs, and walls for control of temperature and shrinkage cracking is given in ACI 318 or in ACI 350R. � c*3�$������Ҍ�7����M�2&20��m>�8����z�]���A�Q\���M�T��d`a��^��{)i�&�2LWl>�s�m1g"Vr$���4#���,�Ȁ $2H��ei�y�ҿ |Va �� ��ս��$N�in��@Z��m5��E3��y$��г�� Section 7.12.3 of ACI 318-02 requires prestressing tendons to be proportioned to provide a minimum average compressive stress of 100 psi (0.7 MPa) on gross concrete area. Design bar cutoffs. In addition to carefully monitoring the temperature of concrete, formwork, reinforcing steel, subbase, subgrade and any other items associated with placement, the surfaces upon which concrete will be placed on should be above 32°F … endstream endobj 1587 0 obj <>stream To control cracks to a … (T or F) 2. The maximum reinforcement ratio is the largest steel area that can be put into concrete members … The code requirements for prestressing tendons used for shrinkage and temperature reinforcement might provide a starting place. [&F�} �**��~�` 0� 0 9oq�*M�S�O��; The portland cement usually had to be aged to comply with a (300-900 mm) 36-72 in. Therefore, regulating the temperature of concrete in cold weather is essential to its proper strength development. l�V�}�l�G'��\M?��2��K~��[�Ěz5�2�/).���K�Q�����s�!oB�m�ڶM���ͷo����&�q;�I|�IM��G� 5=� endstream endobj startxref Note 1: For Line 1, maximum placement temperature is minimum temperature in the table plus 20 °F (11 °C). FOR WALLS: For Vertical Steel. “Cold weather concreting” is defined by the American Concrete Institute (ACI) 306: Guide to Cold Weather Concreting as the procedures relating to the placing, finishing, curing, and protection of concrete during cold weather.Monitoring temperature and meeting cold weather specifications is especially … k��o2*�;e��F�\�/U�e��΂�i���O�Ŕ�vWN_��U�5Pq!��I����+"hȡ��{ �'��A��z���@g�uK$��"�ρ`�b������V-�o覘x>�XJ�6�oh;� ��I�E�;�U�::�9�5�tq�kk�V�I��>�F�lR��q��F6���9X�U�k\l 1H�[email protected]� 0 �:�I K������1��rxF�$;��wR��`M�yÄw�j��w�!���c��d/�D�"����6D��kDK�c�e��U����Q�*f��M�ae����R�rN}�s�{9��!Ě�2��b��s���X�n8���^�k;X=�2|uٷ�`a̪�����]�We������:��f��ϔ��d���ڇ��|a$��C�7�~�߂� Q]�X����T�h���� ��- 1.2—History When concrete was first used in dams, the dams were relatively small and the concrete was mixed by hand. The minimum reinforcement ratio is the lowest possible quantity of steel that should be embedded in structural concrete elements to prevent premature failure after losing the tensile strength. (mm) < 12 in. The temperature of concrete at the time of place- ment should always be near the minimum temperatures given in Chapter 3, Table 3.1. 63 0 obj <> endobj Although there is some cost to all t… For concrete with aggregates less than 3 inches, the thermometer must remain in the fresh concrete sample a minimum of 5 minutes or until the temperature reading stabilizes. The temperature reinforcement shall not be less than ½ inch at nine 9 inch center to center. The American Concrete Institute (ACI) specifies in ACI 306R-16 Guide to Cold Weather Concreting recommended concrete temperatures based on the air temperature. h�ԘooI�?�}�~�(�����V�0��8�;�]�chk`Xf����S=��Mt{���������U ދD�LH/�DHiD&�J�K ��ia<4�[-2+��"s"K.!��"�B�ߙP*5B&�P�� |y�p��6��h���xp��=+t�n�0��T��KѣN�}��a(������'ju�b�O�@����X��)�[B�3������TH�D���=��[��]��t�� •  Minimum – If 3 day average less than 40 degrees, concrete 40 to 55 degrees depending on concrete dimensions. The minimum time period for which the concrete must be protected against freezing is as follows: • When placing regular concrete during "cold weather" conditions, the 50° f concrete temperature shall be maintained at least 3 days. Mixture proportioning for mass concrete is discussed in ACI 211.1. As water evaporates from wet concrete, the total volume of the concrete decreases. We use this provision for lift station slabs that can often be 3ft+ thick. ACI 318 indicates a minimum reinforcement of 0.0018 to control shrinkage and temperature effects. Over the years, I have seen very little to support the validity of having a maximum temperature requirement in hot weather, provided the mix has been properly designed. ACI 306.1-90 Concrete temperatures Minimum concrete temps during the protection period are shown in column (2) Temps of concrete as placed shall not exceed the Column (2) by more than 20°F. The objectives are to prevent damage from early-age freezing (when the concrete is still saturated), to make sure the concrete develops the needed strength, and to limit rapid temperature changes or large temperature differentials that cause cracking. h�bbd```b``����`�$X$D2ՂH�h�Y"���*��$c� ���"@�! 1597 0 obj <>/Filter/FlateDecode/ID[<2DB69072FEC33144A6F05B1E53F6C838><4C29B2CD1984B24C802BAD72EFF78C62>]/Index[1583 29]/Info 1582 0 R/Length 84/Prev 1512536/Root 1584 0 R/Size 1612/Type/XRef/W[1 3 1]>>stream Since the ACI 306R-10 edition, cold weather concrete applies when the air temperature is below 40 degrees or is expected to be below 40 degrees during the protection period. ¥��cD�����dޚ����G��(,�|ʞ�[���l��hrhHe�s��9M���@KPN%TќF�]�ŜPX1��� �,K,+ПaYШ�[B )]S�~�U�e4~X���c�0��%I=�Ԏ�{����B��>R9�LW4�ꏂ���X��B�TS�� �Y妜3�6��2K�q���_����[VN����5��2 ���dr�?B����P��tx���5�� ���w�w��׫�߉$�ݳH�*�F���W{��1�u�,+�Rd�����>_�l*In*)�V�3��e���8�"�Z L�L��od\z3���@I��ڀKV • When placing high-early-strength concrete or concrete with approved accelerators the 50° Concrete work can be accomplished during even the coldest weather as long as the appropriate precautions are taken. (1800 mm) Air temperature Minimum concrete temperature as placed and maintained — 55 °F (13 °C) 50 °F (10 °C) 45 ° (7 °C) 40 F (5 °C) Minimum concrete temperature as mixed for indicated air temperature* k.-���� ��;a ��F�M��!�aU"���V����2�Y�u��2�d4���i�)t½�0:�e�L�������=(��Ҟ ��h����d�s̎�b���ヷ�q��%tQ\�'0 There are also other requirements in ACI 301-10 related to The minimum reinforcement ratio controls the cracking of concrete members. �tj��%�L�R:)���a�w U��g�B�֏�'�l2}xљ-�A��~4�%�?���]�������0>�V�P ƫ0�z>&I�S��ɠ5��Wf�p�L%�� /'��X���:��qͼ�l�dP^�C O�������9�(�t�N���JGW|�'���.ݻ�g��l�3R�y�UO�d����Tf�2�Y����n��v=����=�Cm�#a !X+qY{�7iOc�R� Qualified laboratory technicians shall perform all required laboratory tests. Box 9094 Farmington Hills, Mich. 48333-9094 American Petroleum Institute (API) Production Department 211 N. Ervay, Suite 1700 Dallas, Tex. h�b```g``*f`a`�`[email protected] !�+s|f`�as����v,��a��P�d���0% �-~(飤p:�N��������ALB��@�@ Pc`�� �ŀXlv kK��u�>�4)p�(����#�����)�ˑiXm����Qg`��H3� �b`���` ��3� f min = 0.0025. Concrete Joints • Construction Joints • Expansion Joints (300 mm) 12-36 in. Minimum Concrete Cover: • Concrete Base=3 inches (4” COE) • Concrete Walls=2 inches (3” COE) • Stilling Basin=6” (COE) Temperature and Shrinkage Reinforcing ACI 318 for Grade 60 Steel: As=0.0018bh ACI 350R (use chart), but As(min.)=0.0024bh. hޜT[o� �+cO]�$m�LM��:)�sX��ؑM���� �������w.|��4AQ����/&�ĮQ[!D�FV`�1'D(b� 108 0 obj <>stream 0 S min = 0.0018 (for f y = 60,000 psi). Design temperature & shrinkage reinforcement. �*���GR���Ǚq�f��q4���w�U'XӚ�ҭ�ۊؙ.��Ҍ�m5��յ��5���@ףi�(�Y����`G���ݙ�Q�fk�������d����?t%3����q?z)���J,�m�c��vW���s�e�S����n}Y�-ͅ�. One should take advantage of the opportunity provided by cold weather to place low- temperature concrete. %PDF-1.5 %���� �T���%�26� i�}�$LK��ȫ��7ϳ����:��u�0�N�����d�$�f"��� ���c�e�9��j�E4 For Horizontal Steel. 1583 0 obj <> endobj endstream endobj 64 0 obj <>>> endobj 65 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text]>>/Rotate 0/TrimBox[0.0 0.0 585.0 783.0]/Type/Page>> endobj 66 0 obj <>stream Typical values are between 80° and 95° F as measured by ASTM C 1064-86. The loss of volume causes the concrete to shrink, Standard Test Method for Temperature of Freshly Mixed Hydraulic – Cement Concrete . Concrete Temperature: ACI 301-16 • Mass concrete temperature must be monitored • Place 1 sensor and a backup at: 1) The center of the largest portion of placement 2) 2 in. ACI also limits the rebar spacing of beams and one-way slabs as a function of the steel stress under service loads (fs) in Section 10.6.4. The mixing water will therefore be well above Concrete Temperature Requirements Section size minimum dimension, in. Nonetheless, ASTM C 1064-86 set a maximum limit between 26.7°C and 35°C. ��6�'Hs��i��|��u�S�k�â��N�g�Kݤ~�ԟ�!u�����z�M��R�H�� �(o9�:�4������U�/N The minimum-reinforcement percentage, which is between 0.18 and 0.20%, does not normally control cracks to within generally acceptable design limits. Previous versions specified a maximum concrete temperature of 90°F. ACI 301 has always contained limits on the minimum and maximum temperatures of delivered concrete for both hot and cold weather concrete applications. What is Cold-Weather Concreting? When concrete is being placed below 5 degrees but is not below freezing point, concrete … the temperature of the fresh concrete when preparing speci-mens for strength tests. 0 1611 0 obj <>stream Hot weather is defined as any combination is high ambient temperature, high concrete temperature, low relative humidity, and wind velocity. Some concrete specifications contain a maximum temperature for the freshly mixed concrete as delivered. 5. As recommended in ACI 306R, the mixing temperature should not be more than 15 °F (8 °C) above the values in Lines 2, 3, and 4. � ��0}��9ȾE xĸ�4fĀ1J��5���k�bǫ�\�`E�4�ђ�M��a���&��pS=��Yx��V*B�P�,�~����g�w�4� �l�pE�TN�r1�b�y��X ႎ��{H�2��P�|i$�t �L#�N"�"��=p�nλ5���ٿ�� ACI 301 provides two recommended temperature limits: a) The maximum concrete temperature shall not exceed 160 degrees Fahrenheit during curing, and b) The maximum temperature differential between the center and surface of placement shall not exceed 35 degrees Fahrenheit. R����$�5���ˢa�nw��n�����ۓ֫'=��lH�R6h���=�?ʑߑ���wRo&����>=�o�<[email protected]���i]6h^�׫�X>֘m��5�#�;@z�g � �����j��H㘗��ۨA�l�)�Iǻk֍*�ԯs�5��=���g��X���:��� •  Maximum – Unless otherwise specified, 95 degrees. H�\�[k�@�����/{[email protected]�4i �д?�� 1. Placement temperatures should not be higher than these minimum values by more than 20 F (11 C). American Concrete Institute (ACI) P.O. %%EOF 1905.6.2 Frequencyoftesting.The frequency of conduct-ing strength tests of concrete and the minimum number of tests shall be as specified in ACI 318, Section 5.6.2. 4�c�bQ�{�����Cv�|�{6��ϖð��o^t�a^M����1�L�j��5,��K��-�0C�H���!����uC%|��v�x&7� American Concrete Institute ACI 306 defines cold weather when the following conditions exist for three consecutive days: The average daily temperature falls below 40°F, and Air temperature does not rise above 50°F for more than half a day in any 24-hour period. H���Oo�@���)�H�j���W�"5�TTJ� ACI 350-06 Has the following table for minimum steel for sections thicker than 24 inches. Concrete Temperature Limits ACI 301.5, ACI 301, and ASTM C94 set no temperature limit on fresh concrete in hot weather conditions if precautions are considered in proportioning, production, delivery, placing, and curing concrete. ��ib$�s�҈Z @�p��'��Q8��):>�'�1 ��"�~�jM\d}h�����a�;�3㇕���_#�j�7{�L��K��I� � b���4 �q�LLqf��܌d�J��g���?���.�ʴZ�L(�h&�z� b�$Jy�} ���v;�Q3�]�l����oY4�� �z)܅��/Fk��h�(��b)� ds�������[f�Q8��\���|���w����:z�&�uSBbܕ�3����-K�鈅� Cold weather period, as defined by ACI Committee 306, is when one of the following conditions occur for three consecutive days: Average daily air temperature is less than 40 o F The minimum ratio of required reinforcement is; FOR SLABS: f min = 0.002 (for f y = 40,000 psi). ��L��'��x8h�Z�^�ڞy6Y�P.�v����O�s0vz�e�ŦN���)�=⾑����P�^��?P��*��M��+S���NSW��7��4�i�W3]��.�e������]�zS��}��s���!�g�u)���R������6U�73�f The objective of the ACI 306 is to keep concrete warm, over 5 degrees Celsius, for the first 48 hours, where concrete strength development is critical. 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