Prosecution Insights
Last updated: April 19, 2026
Application No. 18/691,178

POST-TENSIONED EXPANDING CONCRETE WITH FIBERS FOR SLABS

Final Rejection §102§103§112
Filed
Mar 12, 2024
Examiner
HIJAZ, OMAR F
Art Unit
3635
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Ccl Stressing International Ltd.
OA Round
2 (Final)
56%
Grant Probability
Moderate
3-4
OA Rounds
2y 11m
To Grant
90%
With Interview

Examiner Intelligence

Grants 56% of resolved cases
56%
Career Allow Rate
422 granted / 759 resolved
+3.6% vs TC avg
Strong +35% interview lift
Without
With
+34.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
60 currently pending
Career history
819
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
46.5%
+6.5% vs TC avg
§102
22.4%
-17.6% vs TC avg
§112
29.0%
-11.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 759 resolved cases

Office Action

§102 §103 §112
DETAILED ACTION This communication is a first Office Action Non-Final rejection on the merits. Claims 1-15 as originally filed are pending and have been considered below. Claim Objections Claim(s) 6 and 7 are objected to because of the following informalities: Regarding claim 6, at line 2, the recitation “whereby steel fibers”, is understood to mean -- whereby said steel fibers --. Regarding claim 7, at line 8, the recitation “and/or and/or”, is understood to mean -- and/or --. Appropriate correction is required. Drawings The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the “supports” of claims 7-9 and 11-13 must be shown or the feature(s) canceled from the claim(s). No new matter should be entered. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. Claim(s) 2-13, is/are rejected under 35 U.S.C. 112(b), as being indefinite for failing to particularly point out and distinctly claim the subject matter which applicant regards as the invention. Regarding claim 2, at lines 2 and 8-12, the recitations “may be applied”, “may comprise”, and “may lead” render the claim indefinite because the term “may” is ambiguous and it is unclear if the recitations that follow are being positively claimed or are optional. Regarding claims 2-8, 10, and 13, the recitations “preferably”, “further preferred”, and “more preferred” render the claim indefinite because the terms “preferably” and “preferred” is ambiguous and the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. It is further unclear if the recitations that follow are being positively claimed or are optional. Regarding claim 2, at line 33, the recitation “such as” renders the claim indefinite because the term is ambiguous and it is unclear if the recitations that follow are being positively claimed or are optional. Regarding claim 3, at line 16, the recitation “the amount recommend” renders the claim indefinite because it is ambiguous and the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. Regarding claim 3, at line 3, the recitation “may be selected”, renders the claim indefinite because the term “may” is ambiguous and it is unclear if the recitations that follow are being positively claimed or are optional. Regarding claim 5, at line 7, the recitation “is strain hardening in bending” renders the claim indefinite because it is unclear and the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. Regarding claims 7-9, 11, and 12 at lines 2-3, the recitations “said supports” and “the supports” render the claim indefinite because they lack antecedent basis. Regarding claim 8, at line 4, the recitation “can especially be”, renders the claim indefinite because the term “especially” is ambiguous and the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. Regarding claim 8, at line 2, the recitation “may comprise”, renders the claim indefinite because the term “may” is ambiguous and it is unclear if the recitations that follow are being positively claimed or are optional. Regarding claim 9, at line 1, the recitation “it”, renders the claim indefinite because it is unclear as to what “it” is referring to and the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. Regarding claim 9, at line 4, the recitation “especially at”, renders the claim indefinite because the term “especially” is ambiguous and the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. Regarding claim 9, at line 4, the recitations “the points” render the claim indefinite because it lacks antecedent basis. Regarding claim 11, at line 3, the recitation “its”, renders the claim indefinite because it is unclear as to what “its” is referring to and the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. Regarding claim 12, at line 4, the recitation “i.e. lengthwise”, renders the claim indefinite because the term “i.e.” is ambiguous and it is unclear if the recitations that follow are being positively claimed or are optional. Regarding claim 13, at line 2, the recitations “the span” render the claim indefinite because it lacks antecedent basis. Regarding claim 13, at the end of the claim there is a period punctuation which ends the claim, however, following this punctuation there is there following separate unattached paragraph whereby it is unclear if this is meant to be part of the claim: “over a slab with the same span but without fibers and post-tension steel strands and/or wherein the amount of concrete can be reduced for a given slab thickness or a given span over a slab but without fibers and post-tension steel strands by between 5 and 50 %, preferably between 10 or 40 % or between 15 and 35 %, further preferred at least 5 %, 15 %, 20 %, 25 % or 30 % and/or wherein the combination of post-tensioned steel strands and fibers increases the structural capacity for flexure, deflection, shear, punching shear, structural integrity, temperature resistance and/or shrinkage resistance over a slab without steel fibers and/or steel strands. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claim(s) 1-3, 6-9, and 11-14, as best understood, is/are rejected under 35 U.S.C. 103 as being unpatentable over Khayrullin et al. (WO2018084741 A1) with examiner provided Espacenet translation in view of ASTM Publication (A416/A416M-16 2016) hereinafter A416. Regarding claim 1, Khayrullin et al. teaches a concrete slab (load bearing panels; paragraph 3; of concrete; paragraph 57), the slab comprising concrete (paragraph 57) and a combined reinforcement of both post-tension steel cables (post-stressed cables; paragraph 118; it is understood that a post-tensioned strand is by post-stressed after concrete cures) and fibers (steel fibers; paragraph 77), said fibers being steel fibers (steel fibers; paragraph 77) and being present in a dosage ranging from 10 kg/m3 to 75 kg/m3 (paragraph 82), whereby the concrete is expanding concrete (expanded clay concrete; paragraph 71). Khayrullin et al. does not specifically disclose a reinforcement of steel strands having a diameter ranging from 5 mm to 20 mm, having a tensile strength higher than 1700 MPa. A416 teaches a concrete strip (prestressed concrete construction; paragraph 1.1), the strip comprising conventional concrete (paragraph 1.1) and a reinforcement of steel strands (paragraph 1.2) having a diameter ranging from 5 mm to 20 mm (15.24mm; paragraph 1.2), having a tensile strength higher than 1700 MPa (paragraph 1.2). Therefore, from the teaching of A416, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the concrete structure of Khayrullin et al. to include a reinforcement of steel strands having a diameter ranging from 5 mm to 20 mm, having a tensile strength higher than 1700 MPa, as taught by A416, in order to provide steel strands of a known diameter and tensile strength, to maximize the resistance to bending stresses and limiting crack formation on a long concrete slab. Regarding claim 2, Khayrullin et al. teaches a tensile stress of between 5 and 15 % of the final stress may be applied via the post-tension steel strands in the first 24 hours after casting the slab (it is understood that a tensile stress of between 5 and 15 % of the final stress is capable of being applied via the post-tension steel strands in the first 24 hours after casting the slab). With regards to the limitation that the product is formed using a tensile stress of between 5 and 15 % of the final stress applied via the post-tension steel strands in the first 24 hours after casting the slab, etc., the examiner would like to point out that these limitations are drawn to the process of forming the product. Therefore, since this claim is an apparatus claim, the prior art only needs to show the final product. Thus, since Khayrullin et al. as modified teaches all of the structural limitations of the claim, the claim stands rejected. See MPEP 2113. Regarding claim 3, Khayrullin et al. teaches said fibers are steel fibers (steel fibers; paragraph 77). Regarding claim 6, Khayrullin et al. teaches said steel fibers are present in the slab in a dosage ranging from > 25 kg/m3 to 60 or 65 kg/m3, (paragraph 82). Regarding claim 7, Khayrullin et al. teaches said supports are concrete supports (concrete; paragraph 57). Regarding claim 8, Khayrullin et al. teaches the supports comprise columns, walls, piles or beams or any combination thereof (walls; paragraph 3). Regarding claim 9, Khayrullin et al. teaches plastic slip-sheets are not present between the slab and the supports (no plastic slip-sheets are disclosed by Khayrullin et al.). Regarding claim 11, Khayrullin et al. teaches the slab and the supports are either permanently fully connected, so that the slab is not free to move from its supports, permanently fully disconnected, so that the slab is free to move, partially connected, so that the slab is partially free to move in certain directions or temporarily disconnected, so that the slab is free to move at least temporarily (the limitation, as best understood is met as the slab would be capable of being free to move from supports that are not being positively claimed). Regarding claim 12, Khayrullin et al. teaches said supports being arranged to form a regular rectangular pattern or quadrilateral shape (the limitation, as best understood is met as the supports that are not being positively claimed are capable of being arranged to form a regular rectangular pattern or quadrilateral shape), said concrete slab comprising straight zones connecting the supports via the shortest distance in two directions (it is understood that the straight zones are arbitrary locations on the slab that can have an arbitrary straight shape that is capable connecting the supports via the shortest distance in two directions). Regarding claim 13, Khayrullin et al. does not specifically disclose the span of the slabs between two supports for a given thickness is increased by between 5 and 50%. However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention, to contrive any number of desirable ranges wherein the slabs between two supports for a given thickness is increased by between 5 and 50%, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Further, it has been held that by discovering an optimum value of a result, the effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Refer to MPEP § 2144.05. Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to contrive any number of desirable ranges wherein the slabs between two supports for a given thickness is increased by between 5 and 50%, in order to provide the optimal distance between supports to reduce the chance of structural failure. Regarding claim 14, Khayrullin et al. teaches a method to obtain a concrete slab (paragraphs 76-77) according to claim 1 . Claim(s) 4 and 5, as best understood, is/are rejected under 35 U.S.C. 103 as being unpatentable over Khayrullin et al. (WO2018084741 A1) with examiner provided Espacenet translation in view of ASTM Publication (A416/A416M-16 2016) hereinafter A416, and further in view of Lambrechts et al. (U.S. Pub. No. 2013/0269572). Regarding claim 4, Khayrullin et al. as modified does not specifically disclose said steel fibers comprise a straight middle portion that have a tensile strength above 1400 MPa. Lambrechts et al. discloses a steel fiber for reinforcing concrete (abstract) wherein said steel fibers comprise a straight middle portion (figure 4) that have a tensile strength above 1400 MPa (paragraph 67). Therefore, from the teaching of Lambrechts et al., it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the modified concrete structure of Khayrullin et al. such that said steel fibers comprise a straight middle portion that have a tensile strength above 1400 MPa, in order to optimize the performance of the fibers under high loads, depending on the design requirements of the structure for enhanced efficiency. Regarding claim 5, Khayrullin et al. as modified does not specifically disclose said steel fibers comprise anchorage ends at both ends, said anchorage ends each comprise three or four bent sections. Lambrechts et al. discloses a steel fiber for reinforcing concrete (abstract) wherein said steel fibers comprise anchorage ends (at 404) at both ends (figure 4), said anchorage ends each comprise three or four bent sections (figure 4). Therefore, from the teaching of Lambrechts et al., it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the modified concrete structure of Khayrullin et al. such that said steel fibers comprise anchorage ends at both ends, said anchorage ends each comprise three or four bent sections, in order to optimize the anchoring performance of the fibers under high loads, depending on the design requirements of the structure for enhanced efficiency. Claim(s) 10, as best understood, is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Khayrullin et al. (WO2018084741 A1) with examiner provided Espacenet translation in view of ASTM Publication (A416/A416M-16 2016) hereinafter A416, and further in view of in view of Kollegger et al. (U.S. Pub. No. 2009/0301011). Regarding claim 10, Khayrullin et al. as modified does not specifically disclose the post-tension steel strands are used for bonded or unbonded post-tensioning. Kollegger et al. discloses a reinforced concrete structure that includes bonded or unbonded post-tensioning (paragraph 56). Therefore, from the teaching of Kollegger et al., it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the modified concrete structure of Khayrullin et al. such that the post-tension steel strands are used for bonded or unbonded post-tensioning, as taught by Kollegger et al., in order to further prevent cracks and enable a longer span of the concrete slab, for greater structural and architectural efficiency. Claim(s) 15, as best understood, is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Khayrullin et al. (WO2018084741 A1) with examiner provided Espacenet translation in view of ASTM Publication (A416/A416M-16 2016) hereinafter A416, and further in view of in view of Yu et al. (CN 111663434 A) with examiner provided Espacenet translation. Regarding claim 15, Khayrullin et al. teaches casting a concrete slab, the slab comprising concrete (paragraph 57) and a combined reinforcement of both post-tension steel cables (post-stressed cables; paragraph 118; it is understood that a post-tensioned strand is by post-stressed after concrete cures) and fibers (steel fibers; paragraph 77), said fibers being steel fibers (steel fibers; paragraph 77) and being present in a dosage ranging from 10 kg/m3 to 75 kg/m3 (paragraph 82), whereby the concrete is expanding concrete (expanded clay concrete; paragraph 71). Khayrullin et al. does not specifically disclose a reinforcement of steel strands having a diameter ranging from 5 mm to 20 mm, having a tensile strength higher than 1700 MPa. A416 teaches a concrete strip (prestressed concrete construction; paragraph 1.1), the strip comprising conventional concrete (paragraph 1.1) and a reinforcement of steel strands (paragraph 1.2) having a diameter ranging from 5 mm to 20 mm (15.24mm; paragraph 1.2), having a tensile strength higher than 1700 MPa (paragraph 1.2). Therefore, from the teaching of A416, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the concrete structure of Khayrullin et al. to include a reinforcement of steel strands having a diameter ranging from 5 mm to 20 mm, having a tensile strength higher than 1700 MPa, as taught by A416, in order to provide steel strands of a known diameter and tensile strength, to maximize the resistance to bending stresses and limiting crack formation on a long concrete slab. In addition, Khayrullin et al. does not specifically disclose applying a tensile stress of between 5 and 15 % of the final stress in the post-tension steel strands in the first 24 hours after casting the slab. Yu et al. discloses tensioning assembly for prestressed concrete (paragraph 1) including applying a tensile stress of between 5 and 15 % of the final stress in the post-tension steel strands after casting the slab (paragraph 23). Although Yu et al. does not specifically disclose apply the tensile stress in the first 24 hours, the examiner takes official notice that it is well-known in the art to apply tensile stress for post-tensioning within the first 24 hours after casting in order to control for early shrinkage cracking to provide for sufficient strength depending on the design requirements of the concrete structure. Therefore, from the teaching of Yu et al., it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify the concrete structure of Khayrullin et al. to include applying a tensile stress of between 5 and 15 % of the final stress in the post-tension steel strands in the first 24 hours after casting the slab, as taught by Yu et al., in order to optimize the initial strength of the post-tensioned structure to control for early shrinkage cracking to provide for sufficient strength of the concrete structure. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. The cited patents listed on the included form PTO-892 further show the state of the art with respect to concrete structures in general. Any inquiry concerning this communication or earlier communications from the examiner should be directed to OMAR HIJAZ whose telephone number is (571)270-5790. The examiner can normally be reached on 8-6 EST Monday-Friday. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Brian Mattei can be reached on (571) 270-3238. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /OMAR F HIJAZ/Examiner, Art Unit 3633
Read full office action

Prosecution Timeline

Mar 12, 2024
Application Filed
Nov 18, 2025
Non-Final Rejection — §102, §103, §112
Mar 04, 2026
Response Filed
Apr 10, 2026
Final Rejection — §102, §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
56%
Grant Probability
90%
With Interview (+34.8%)
2y 11m
Median Time to Grant
Moderate
PTA Risk
Based on 759 resolved cases by this examiner. Grant probability derived from career allow rate.

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