Company: ACA
Filing Date: 2025-04-01
Form Type: DEFA14A
Source: 0001739445-25-000059
Chunk: 0

Company: Arcosa, Inc.
Filing Date: 2025-04-01
Form: DEFA14A
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549
<div align='center'>________________________</div>

#### SCHEDULE 14A INFORMATION

#### Proxy Statement Pursuant to Section 14(a) of the

#### Securities Exchange Act of 1934
<div align='center'>(Amendment No. )

________________________</div>

| Filed by the Registrantþ   |     |                                                                                 |     | Filed by a party other than the Registrant¨ |
| Check the appropriate box: |     |                                                                                 |     |                                             |
| ¨                          |     | Preliminary Proxy Statement                                                     |     |                                             |
| ¨                          |     | Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) |     |                                             |
| ¨                          |     | Definitive Proxy Statement                                                      |     |                                             |
| þ                          |     | Definitive Additional Materials                                                 |     |                                             |
| ¨                          |     | Soliciting Material Pursuant to §240.14a-12                                     |     |                                             |

#### Arcosa, Inc.
<div align='center'>(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if Other Than The Registrant)</div>

| Payment of Filing Fee (Check the appropriate box): |     |                                                                                                     |
| þ                                                  |     | No fee required.                                                                                    |
| ¨                                                  |     | Fee paid previously with preliminary materials.                                                     |
| ¨                                                  |     | Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11 |