J. Thomas Hill
Chairman, President and Chief Executive Officer at Vulcan Materials
Thank you, Mark, and thank all of you for your interest in Vulcan Materials today. Our results through the first half of 2023 highlight both the attractive fundamentals of our aggregates-led business and Vulcan's commitment to compounding profitability through our solid execution of our Vulcan web selling and both with operating strategic disciplines. I'm proud of our teams for delivering yet another quarter of improvement in our trailing 12-month aggregates cash gross profit per ton. That marks 20 of the last 22 quarters. This exceptional execution, coupled with better-than-expected demand environment gives us confidence in our ability to deliver between $1.9 billion and $2 billion in adjusted EBITDA this year. In the quarter, we generated $595 million of adjusted EBITDA, which is a 32% improvement over the prior year.
Gross margin expanded by 480 basis points, and importantly, each product line delivered year-over-year improvement. In the Aggregates segment, gross margin improved by 290 basis points. Cash gross profit per ton improved by 22% with healthy year-over-year price improvement and moderating year-over-year cost increases. Shipments declined a modest 1% in the quarter, but were varied across markets. On one hand, we saw a solid growth in our key southeastern markets, where we have the most attractive Aggregates footprint. And we were pleased with the rebound of sales in California after a very wet first quarter. On the other hand, weather continued to be a challenge in Texas. And remember, softer residential activity wait on most markets. All geographies benefited from the continued strong underlying price environment. Our mix adjusted sales price improved 15% in the quarter.
Attractive price growth should continue to drive improvement in our unit profitability as we progress through the back half of this year and into next year. In Asphalt, cash gross profit nearly tripled from the prior year to $66 million, and cash unit profitability improved over $10 a ton. Volume growth of 16%, price improvement of 9% and lower liquid asphalt costs all contribute to the stable results. Gross margin improved almost 1,200 basis points. Concrete cash unit profitability improved by 24% in the quarter, and this is despite lower volumes that were impacted by the slowdown in residential construction activity. Prior year Concrete segment benefited for the contribution of the now divested New York, New Jersey and Pennsylvania Concrete operations. Now starting with residential. Let me provide a few thoughts about each end market. To date, the impact of the slowdown in residential activity has not been as significant as most of us initially feared. Recent permits and starts were showing that some areas have reached the bottom, and the cinema among homebuilders is much improved.
These trends along with the solid underlying fundamentals for residential demand growth such as low inventories, favorable demographic trends and employment growth in our market suggests that single-family demand will bottom in the second half of this year and be -- and then start recovering thereafter. In the private nonresidential construction segment, starts remained at healthy levels, with particular strength in large manufacturing and industrial projects. Our strong Southeastern footprint and logistics innovation efforts are making us a supplier of choice on many of these projects. As an example, we have booked and are currently shipping to projects such as battery plants, electric vehicle manufacturing facilities, LNG facilities and large warehouse parks. On the public side, demand is unfolding largely as we expected, Funding from the infrastructure investment and Jobs Act is beginning to flow through and the pipeline is building with trailing 12-month highway starts up over 20%. 2024 state budgets are at very healthy levels. And internally, our bookings and backlog reflect this increased activity. The level of this year's shipments will depend upon how quickly this increased activity converts to shipments.
We expect accelerating growth into next year and continued growth for the next several years. Trailing 12-month other infrastructure starts are also over -- up over 20%. In addition to significant IIJA funding for water, energy, ports and shipments, strong state and local revenue support growth in non-highway investments. Based on the improved private demand backdrop, our first half shipment -- and our first half shipments, we now expect Aggregates volumes to decline between 1% to 4% in 2023 and as compared to our initial expectations of a decline between 2% and 6%. Of course, regardless of the demand environment, our focus is to consistently improve unit profitability and grow earnings that we create value for our shareholders. We're well positioned to do exactly that this year and deliver approximately 20% year-over-year improvement in both our cash gross profit per ton and adjusted EBITDA.
And now I'll turn the call over to Mary Andrews for some additional commentary on our second quarter and an update for 2023 outlook.