private property Static is getting touched value!

Question

I have the class below:

<?php

namespace CONSTANTES;

class Constantes {

    private $livre = true;

    private $util;

    private $site = array (

        "dominio"           => "crud.com.br",
        "www"               => "www.crud.com.br",               
        "http"              => "http://www.crud.com.br",                
        "tituloSite"        => "CRUD SITE",     
        "tituloAdmin"       => "CRUD Administração",        
        "tituloLoja"        => "CRUD LOJA", 
        "descricao"         => "???",
        "keywords"          => "???",
        "fundacao"          => "???",       
        "ano"               => "2018",
        "proprietario"      => "???",
        "proprietarioDcto"  => "???"

    );


    private $siteEndereco = array (

        "rua"         => "???",
        "numero"      => "???",
        "complemento" => "???",
        "bairro"      => "???",
        "cidade"      => "???",
        "estado"      => "???",
        "cep"         => "???"

    );

    private $siteEnderecoCompleto;

    private $siteTelefones = array (
        "ddd"         => "???",
        "tel"         => "???",
        "cel"         => "???"
    );

    private $siteRedesSocias = array (
        "facebook"    => "http://www.facbook.com/crud",
        "instagram"   => "http://www.instagram.com/crud",
        "whatsapp"    => "???"
    );

    private $imgDir = "_img";

    private $charset = "UTF-8";

    public function __construct($_util) {

         if($this->livre == false) {
             header("Location: ".$_SERVER["SERVER_PATH"]."/manutencao.php");
             exit;
         }  

        $this->util = $_util;

        $this->siteEnderecoCompleto = 
                                      $this->siteEndereco["rua"]. ", ";
                                      $this->siteEndereco["numero"]. ", ";
                                      $this->siteEndereco["complemento"]. ", ";
                                      $this->siteEndereco["bairro"]. ", ";
                                      $this->siteEndereco["cidade"]. ", ";
                                      $this->siteEndereco["estado"]. ", ";
                                      $this->util->formataCep($this->siteEndereco["cep"]). ", ";

    }

    public function getLivre() {

        return $this->livre;

    }   

    public function getSite() {

        return $this->site;

    }

    public function getSiteEndereco() {

        return $this->siteEndereco;

    }

    public function getSiteEnderecoCompleto() {

        return $this->getSiteEnderecoCompleto();

    }

    public function getSiteTelefones() {

        return $this->siteTelefones;

    }

    public function getSiteRedesSociais() {

        return $this->siteRedesSocias;

    }

    public function getImagemDir() {

        return $this->imgDir;

    }

    public function getCharset() {

        return $this->charset;

    }

}

?>

As it is a class of properties that are immutable via code. That is, they are constants. I would add static in them. In the form below:

<?php

namespace CONSTANTES;

class Constantes {

    static private $livre = true;

    static private $util;

...

But this practice changes the value of $livre for false;

How can I do that?

I also tried to:

static private final $livre = true;

It’s the same!