SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Argos SEM, LLC (Last) (First) (Middle) 251 LITTLE FALLS DRIVE (Street) WILMINGTON DE 19808 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 01/12/2024	3. Issuer Name and Ticker or Trading Symbol Summit Materials, Inc. [ SUM ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Class A Common Stock(1)	6,172,416(2)	I	Held by Valle Cement Investments Inc.
Class A Common Stock(1)	48,547,584(3)	D
Series A Non-Convertible Preferred Stock(1)	1(4)	I	Held by Cementos Argos S.A.

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* Argos SEM, LLC (Last) (First) (Middle) 251 LITTLE FALLS DRIVE (Street) WILMINGTON DE 19808 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Valle Cement Investments, Inc. (Last) (First) (Middle) CAPITAL PLAZA BUILDING, 15TH FLOOR, PASEO ROBERTO MOTTA, COSTA DEL ESTE (Street) PANAMA R1 0816-02984 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. This Form 3 is filed jointly by (i) Grupo Argos S.A., a sociedad anonima incorporated in the Republic of Colombia ("Grupo Argos"), (ii) Cementos Argos S.A., a sociedad anonima incorporated in the Republic of Colombia ("Cementos Argos"), (iii) Argos SEM, LLC, a Delaware limited liability company ("Argos SEM") and (iv) Valle Cement Investments Inc., a sociedad anonima incorporated in the Republic of Panama ("Valle Cement" and collectively with Grupo Argos, Cementos Argos and Argos SEM, the "Reporting Persons"). Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of its pecuniary interest therein.

2. Represents securities of Summit Materials, Inc., a Delaware corporation (the "Issuer"), directly owned by Valle Cement, which is a wholly-owned subsidiary of Cementos Argos S.A., which is a majority-owned subsidiary of Grupo Argos. Grupo Argos, as the controlling shareholder of Cementos Argos, which in turn is the sole shareholder of Valle Cement, has the power to vote and to dispose of the shares of Class A common stock, par value $0.01 per share ("Class A Common Stock"), of the Issuer directly owned by Valle Cement. As a result of this relationship, Grupo Argos may be deemed to be an indirect beneficial owner of the securities that are beneficially owned by Valle Cement. By reason of the provisions of Rule 13d-3 of the Securities Exchange Act of 1934, as amended, each of the Reporting Persons may be deemed to beneficially own the shares of Common Stock of the Issuer directly owned by Valle Cement.

3. Represents securities of the Issuer, directly owned by Argos SEM, which is a wholly-owned subsidiary of Cementos Argos, which is a majority-owned subsidiary of Grupo Argos. Grupo Argos, as the controlling shareholder of Cementos Argos, which in turn is the sole shareholder of Argos SEM, has the power to vote and to dispose of the shares of Class A Common Stock of the Issuer directly owned by Argos SEM. As a result of this relationship, Grupo Argos may be deemed to be an indirect beneficial owner of the securities that are beneficially owned by Argos SEM. By reason of the provisions of Rule 13d-3 of the Securities Exchange Act of 1934, as amended, each of the Reporting Persons may be deemed to beneficially own the shares of Common Stock of the Issuer directly owned by Argos SEM.

4. Represents securities of the Issuer, directly owned by Cementos Argos, which is a majority-owned subsidiary of Grupo Argos. Grupo Argos, as the controlling shareholder of Cementos Argos, has the power to vote and to dispose of the share of Series A Non-Convertible Preferred Stock of the Issuer directly owned by Cementos Argos. As a result of this relationship, Grupo Argos may be deemed to be an indirect beneficial owner of the securities that are beneficially owned by Cementos Argos. By reason of the provisions of Rule 13d-3 of the Securities Exchange Act of 1934, as amended, each of the Reporting Persons may be deemed to beneficially own the shares of Series A Non-Convertible Preferred Stock of the Issuer directly owned by Cementos Argos.

Remarks:

	/s/ Grupo Argos S.A., By: Rafael Olivella, Title: Vice President	01/22/2024
	/s/ Cementos Argos S.A., By: Felipe Aristizabal, Title: Vice President	01/22/2024
	/s/ Valle Cement Investments Inc., By: Gustavo Adolfo Uribe, Title: President	01/22/2024
	/s/ Argos SEM, LLC, By: Gustavo Adolfo Uribe, Title: President	01/22/2024
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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