D.C. Mayor Marion Barry's proposed 1984 construction program, reflecting the Reagan administration's decision to phase out federal loans for District capital projects focuses on renovation, replacement or repair of existing structures.

The mayor has asked the council to approve $111 million in projects for the coming fiscal year, including new buildings to replace a police station in Anacostia, and the city's oldest fire station, Engine Company No. 12, at North Capitol Street and Florida Avenue NW, and providing new fire equipment for the unit.

While the budget provides for replacing some existing structures, it proposes no major projects that are not already on the drawing boards.

Barry has also asked for $11.8 million in renovations to relieve overcrowding, in part due to court-ordered improvements, at the District's prison facility at Lorton, including $5.2 million to convert the training academy into a minimum security prison and $3.4 million to create a maximum security unit at Youth Center No. 1.

The proposal also seeks approval for $3.5 million to build a new central laboratory for the District at D.C. General Hospital, replacing the one now housed at the Municipal Center.

The vast majority of the proposed building funds--$76 million or more than two-thirds--would go for finishing already approved construction projects and for continuing repairs of the District's streets and bridges, at a cost of $24 million.

The schools would receive the second highest amount, $19.8 million, under the mayor's proposal, including $8.5 million to bring school heating equipment in compliance with pollution laws, $7 million to complete the construction of the Bell Career Center, the Ellington School of the Arts and a prevocational center for the handicapped and $2 million to repair leaking school roofs.

The mayor cut about $6 million from the school board's capital budget request.

A significant new aspect of the capital improvements budget is $5.5 million that would be alloted for an economic development fund as part of a program to encourage increased private development in the District, a top priority of Barry's second administration. No funds were appropriated this year for that fund.

Also aimed at the private business community, although not part of the capital improvements budget, is the mayor's request for $2.7 million to allow the new Washington Convention Center to purchase kitchen facilities and cooking equipment from the private firm running the center's food service operation.

Convention center officials said that they expect the new facility to generate enough revenue from rental fees and special hotel taxes to cover the full $2.7 million.

In addition to the $111 million in projects, the mayor is asking the council to authorize in the coming year, he is seeking $115 million in capital loans from the federal government in fiscal 1984. Nearly all of the loans being sought will be used to finance capital projects authorized in previous budgets.

For example, the mayor is not asking the council to approve spending new Metro construction funds. However, Metro is expected to receive a significant amount--more than $20 million--of the federal loans the city is seeking in fiscal 1984.

The proposed construction budget represents the mayor's second attempt to lay the groundwork for a major transformation of the way the city finances its multi-million dollar construction program.

Until the current fiscal year, the city had unlimited authority to pay for its new buildings and other public works projects with loans from the U.S. Treasury, which has lent the District about $1.6 billion.

"This is the last year we can go to the Treasury to borrow money for capital improvements," said Gladys W. Mack, a top Barry administration budget official.

Mack and other city officials said that the District plans to raise money for future capital projects by selling general obligation bonds. Local governments usually rely on general obligation bonds to finance most capital projects, but the District's troubled finances have prevented it from selling bonds in the past.