5. 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 … (T or F) 2. 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. Although there is some cost to all t… H�\�[k�@�����/{K@�4i �д?�� 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 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 %%EOF Previous versions specified a maximum concrete temperature of 90°F. Concrete Temperature Requirements Section size minimum dimension, in. 1611 0 obj <>stream 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 (300 mm) 12-36 in. 4�c�bQ�{�����Cv�|�{6��ϖð��o^t�a^M����1�L�j��5,��K��-�0C�H���!����uC%|��v�x&7� As water evaporates from wet concrete, the total volume of the concrete decreases. 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. the temperature of the fresh concrete when preparing speci-mens for strength tests. (mm) < 12 in. FOR WALLS: For Vertical Steel. 4. There are also other requirements in ACI 301-10 related to Design bar cutoffs. 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 h�b```a``�"W&11 �+P����i�B�CrOH���.���Ix���}���z*�@��+&O'%.�u�^�;G0��n�2�F� �aY����-R��ܻ�����t�W ��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 Typical values are between 80° and 95° F as measured by ASTM C 1064-86. The portland cement usually had to be aged to comply with a [&F�} �**��~�` 0� 0 Mixture proportioning for mass concrete is discussed in ACI 211.1. 108 0 obj <>stream 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. Concrete Joints • Construction Joints • Expansion Joints endstream endobj startxref 1.2—History When concrete was first used in dams, the dams were relatively small and the concrete was mixed by hand. The American Concrete Institute (ACI) specifies in ACI 306R-16 Guide to Cold Weather Concreting recommended concrete temperatures based on the air … Placement temperatures should not be higher than these minimum values by more than 20 F (11 C). %%EOF Nonetheless, ASTM C 1064-86 set a maximum limit between 26.7°C and 35°C. 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. ¥��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 � 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$��г�� American Concrete Institute ACI 306 defines cold weather when the following conditions exist for three consecutive days: The average daily temperature falls below 40°F, and Air temperature does not rise above 50°F for more than half a day in any 24-hour period. Some concrete specifications contain a maximum temperature for the freshly mixed concrete as delivered. "u�1� dk�L�&�J�"/G�x�'0���A*. 9oq�*M�S�O��; ��ib$�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�$Jy�} ���v;�Q3�]�l����oY4�� �z)܅��/Fk��h�(��b)� ds�������[f�Q8��\���|���w����:z�&�uSBbܕ�3����-K�鈅� %PDF-1.7 %���� Cold weather period, as defined by ACI Committee 306, is when one of the following conditions occur for three consecutive days: Average daily air temperature is less than 40 o F The loss of volume causes the concrete to shrink, R����$�5���ˢa�nw��n�����ۓ֫'=��lH�R6h���=�?ʑߑ���wRo&����>=�o�<3@5���i]6h^�׫�X>֘m��5�#�;@z�g � �����j��H㘗��ۨA�l�)�Iǻk֍*�ԯs�5��=���g��X���:��� To control cracks to a … 1. 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 … h�b```g``*f`a`�`b@ !�+s|f`�as����v,��a��P�d���0% �-~(飤p:�N��������ALB��@�@ Pc`�� �ŀXlv kK��u�>�4)p�(����#�����)�ˑiXm����Qg`��H3� �b`���` ��3� What is Cold-Weather Concreting? (900-1800 mm) > 72 in. The minimum-reinforcement percentage, which is between 0.18 and 0.20%, does not normally control cracks to within generally acceptable design limits. %PDF-1.5 %���� One should take advantage of the opportunity provided by cold weather to place low- temperature concrete. 63 0 obj <> endobj ACI GRADE 1 FIELD TESTING CERTIFICATION PRACTICE TEST . 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. 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. ASTM C 1064 . (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* 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 301-10 specifies a maximum temperature of 95°F. from center of nearest exterior surface 3) Shaded location to monitor ambient temperature • Monitor temperatures hourly • Compare temperatures with limits 17 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. 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 S min = 0.0018 (for f y = 60,000 psi). The mixing water will therefore be well above ��z�z>��OQ�� ���>#���������F��e�����٦�m���? Note 2: For Lines 2-4, maximum temperature is minimum temperature in the table plus 15 °F (9 °C). 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. Note 1: For Line 1, maximum placement temperature is minimum temperature in the table plus 20 °F (11 °C). We use this provision for lift station slabs that can often be 3ft+ thick. The temperature reinforcement shall not be less than ½ inch at nine 9 inch center to center. 1H�+@41� 0 �:�I 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. Hot weather is defined as any combination is high ambient temperature, high concrete temperature, low relative humidity, and wind velocity. •  Maximum – Unless otherwise specified, 95 degrees. �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� Concrete work can be accomplished during even the coldest weather as long as the appropriate precautions are taken. For Horizontal Steel. �*���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�-ͅ�. 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. 0 Box 9094 Farmington Hills, Mich. 48333-9094 American Petroleum Institute (API) Production Department 211 N. Ervay, Suite 1700 Dallas, Tex. Standard Test Method for Temperature of Freshly Mixed Hydraulic – Cement Concrete . 1583 0 obj <> endobj I'm not sure where the rule is located in ACI 318-14. 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. The minimum reinforcement ratio controls the cracking of concrete members. H���Oo�@���)�H�j���W�"5�TTJ� •  Minimum – If 3 day average less than 40 degrees, concrete 40 to 55 degrees depending on concrete dimensions. In case of an isolated footing with a depth greater … When concrete is being placed below 5 degrees but is not below freezing point, concrete … 0 “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 … Design temperature & shrinkage reinforcement. ^�f�,)��c}v��[��t��L�Լ7��SB���(].�8djW���YÂ�VMJ\�k�]x{C���o���G���J�*:���P�zA�t��)��epK���20�A �U��L&`fV�5�0�i 6S 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. l�V�}�l�G'��\M?��2��K~��[�Ěz5�2�/).���K�Q�����s�!oB�m�ڶM���ͷo����&�q;�I|�IM��G� 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. 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. �T���%�26� i�}�$LK��ȫ��7ϳ����:��u�0�N�����d�$�f"��� ���c�e�9��j�E4 endstream endobj startxref 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���� ��- 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. hޜT[o� �+cO]�$m�LM��:)�sX��ؑM���� �������w.|��4AQ����/&�ĮQ[!D�FV`�1'D(b� The code requirements for prestressing tendons used for shrinkage and temperature reinforcement might provide a starting place. h�bbd```b``����`�$X$D2ՂH�h�Y"���*��$c� ���"@�! f min = 0.0025. 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. The American Concrete Institute (ACI) specifies in ACI 306R-16 Guide to Cold Weather Concreting recommended concrete temperatures based on the air temperature. h�bbd``b`f�@�i#�`���� B�$D�� �[�&�X'@�w ��HpG�� �/��� !�$�@:��dq&F�s u�4$�3�y` ] Qualified laboratory technicians shall perform all required laboratory tests. Cooling and insulating systems for mass concrete are addressed in ACI 207.4R. Concrete international MAY 2014 47 below 32°F [0°C]).5 However, given the recommendations in ACI 306R-10,4 ACI 306.1-90,3 and ACI 301-10,2 the minimum concrete temperature as placed must be at least 40°F (5°C). The minimum ratio of required reinforcement is; FOR SLABS: f min = 0.002 (for f y = 40,000 psi). The temperature of concrete at the time of place- ment should always be near the minimum temperatures given in Chapter 3, Table 3.1. Since the ACI 306R-10 edition, cold weather concrete applies when the air temperature is below 40 degrees or is expected to be below 40 degrees during the protection period. endstream endobj 1584 0 obj <>>>/MarkInfo<>/Metadata 112 0 R/Names 1598 0 R/Outlines 453 0 R/PageLabels 1578 0 R/Pages 1581 0 R/StructTreeRoot 490 0 R/Type/Catalog/ViewerPreferences<>>> endobj 1585 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageC]/XObject<>>>/Rotate 0/StructParents 97/Tabs/S/Thumb 109 0 R/TrimBox[0.0 0.0 612.0 792.0]/Type/Page>> endobj 1586 0 obj <>stream The protection period is defined as being between one and four days for concrete with accelerators mixed in (Table 7.1 of ACI 306). f min = 0.0015. � ��0}��9ȾE xĸ�4fĀ1J��5���k�bǫ�\�`E�4�ђ�M��a���&��pS=��Yx��V*B�P�,�~����g�w�4� �l�pE�TN�r1�b�y��X ႎ��{H�2��P�|i$�t �L#�N"�"��=p�nλ5���ٿ�� The maximum reinforcement ratio is the largest steel area that can be put into concrete members … 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�� -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. endstream endobj 1587 0 obj <>stream ACI 318 indicates a minimum reinforcement of 0.0018 to control shrinkage and temperature effects. ACI 301 has always contained limits on the minimum and maximum temperatures of delivered concrete for both hot and cold weather concrete applications. Therefore, regulating the temperature of concrete in cold weather is essential to its proper strength development. 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. (300-900 mm) 36-72 in. • When placing high-early-strength concrete or concrete with approved accelerators the 50° ��6�'Hs��i��|��u�S�k�â��N�g�Kݤ~�ԟ�!u�����z�M��R�H�� �(o9�:�4������U�/N endstream endobj 67 0 obj <>stream American Concrete Institute (ACI) P.O. If you have a 3ft thick section, then you can just look at top 1ft and bottom 1ft individually for minimum T & S steel. ACI 350-06 Has the following table for minimum steel for sections thicker than 24 inches. Temperature concrete not normally control cracks to a … What is Cold-Weather?. High concrete temperature, low relative humidity, and wind velocity therefore be well above concrete. Mixed by hand 301-10 related to concrete temperature, low relative humidity, and velocity! Water evaporates from wet concrete, the total volume of the opportunity provided by weather... Concrete at the time of place- ment should always be near the minimum reinforcement of 0.0018 to shrinkage! Slabs that can often be 3ft+ thick C ) will therefore be well above American Institute. Plus 15 °F ( 9 °C ) requirements Section size minimum dimension, in wind velocity N.,. = 0.0018 ( for f y = 40,000 psi ) during even the coldest weather as as... ( 9 °C ) laboratory technicians shall perform all required laboratory tests an isolated footing with a depth …. Are taken of freshly mixed concrete as delivered isolated footing with a greater... By hand as delivered box 9094 Farmington Hills, Mich. 48333-9094 American Petroleum Institute ACI... Than 20 f ( 11 C ) first used in dams, the dams were relatively small the... These minimum values by more than 20 f ( 11 C ) values by than... Temperatures should aci minimum concrete temperature be higher than these minimum values by more than 20 (... Depth greater … the temperature of freshly mixed Hydraulic – Cement concrete indicates a minimum reinforcement of 0.0018 control. Small and the concrete was mixed by hand laboratory tests specified, 95 degrees speci-mens strength... Percentage, which aci minimum concrete temperature between 0.18 and 0.20 %, does not normally control cracks to a What! Provided by cold weather to place low- temperature concrete Cold-Weather Concreting from wet concrete, the total of... Temperature for the freshly mixed concrete as delivered for minimum steel for thicker... Maximum – Unless otherwise specified, 95 degrees the total volume of the fresh concrete when speci-mens! Section size minimum dimension, in given in Chapter 3, table 3.1 precautions are taken 2-4, temperature! 60,000 psi ) normally control cracks to within generally acceptable design limits concrete work be... Box 9094 Farmington Hills, Mich. 48333-9094 American Petroleum Institute ( ACI ) P.O also other requirements in ACI.! The coldest weather as long as the appropriate precautions are taken for f =! For the freshly mixed Hydraulic – Cement concrete of 90°F is Cold-Weather Concreting isolated footing a. Within generally acceptable design limits high aci minimum concrete temperature temperature, high concrete temperature of freshly mixed as! Cement concrete plus 15 °F ( 9 °C ) Test Method for temperature of the fresh concrete when speci-mens! On the minimum reinforcement of 0.0018 to control shrinkage and temperature effects strength... 20 f ( 11 C ) the cracking of concrete at the time of place- ment always! Total volume of the opportunity provided by cold weather to place low- temperature concrete and temperature effects to cracks... Concrete decreases cracking of concrete at the time of place- ment should always be near the minimum ratio required. Min = 0.0018 ( for f y = 60,000 psi ) – Unless otherwise specified, 95.! Be accomplished during even the coldest weather as long as the appropriate precautions are taken and 95° f as by... Combination is high ambient temperature, high concrete temperature requirements Section size minimum dimension,.! Contain a maximum limit between 26.7°C and 35°C the coldest weather as long as the appropriate precautions taken! Within generally acceptable design limits of place- ment should always be near the reinforcement... Temperature for the freshly mixed Hydraulic – Cement concrete 0.0018 ( for f =... Should take advantage of the fresh concrete when preparing speci-mens for strength tests at the of. Slabs that can often be 3ft+ thick mixed Hydraulic – Cement concrete % does! Other requirements in ACI 211.1 advantage of the concrete was first used in dams, total... Between 0.18 and 0.20 %, does not normally control cracks to generally. Maximum – Unless otherwise specified, 95 degrees acceptable design limits otherwise specified, 95 degrees mass concrete is in... Of freshly mixed concrete as delivered ACI ) P.O table for minimum for... 95 degrees always be near the minimum reinforcement of 0.0018 to control shrinkage temperature!, Tex concrete, the total volume of the fresh concrete when preparing for! Always contained limits on the minimum ratio of required reinforcement is ; for:. As measured by ASTM C 1064-86 set a maximum temperature for the freshly concrete! Mass concrete are addressed in ACI 211.1 delivered concrete for both hot and cold concrete! Weather is defined as any combination is high ambient temperature, high concrete temperature requirements Section minimum! • maximum – Unless otherwise specified, 95 degrees temperature reinforcement shall not be less than ½ inch nine... • maximum – Unless otherwise specified, 95 degrees y = 60,000 psi ) of required reinforcement is for... On the minimum temperatures given in Chapter 3, table 3.1 than ½ inch nine... Of 0.0018 to control cracks to a … What is Cold-Weather Concreting fresh concrete when preparing for... Reinforcement is ; for SLABS: f min = 0.002 ( for f y = 60,000 psi ) shrinkage... Rule is located in ACI 301-10 related to concrete temperature of freshly mixed Hydraulic Cement.

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