using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		var texto  = "13032015joao14032014Juca25";
		List<string> partes = new List<string>(Regex.Split(texto, @"(?<=\G.{12})",
RegexOptions.Multiline));
 
		foreach (var parte in partes){
			Console.WriteLine(parte);
            // 13032015joao
            // 14032014Juca
            // 25
        }
        Console.ReadLine();
	}
}

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